Examples with solutions for The Quadratic Formula: Equations with variables on both sides

Exercise #1

Solve the following equation:

x2+3x3=x x^2+3x-3=x

Video Solution

Step-by-Step Solution

To solve the quadratic equation x2+3x3=x x^2 + 3x - 3 = x , we first rearrange it to standard form.

Step 1: Move all terms to one side of the equation:
x2+3x3x=0 x^2 + 3x - 3 - x = 0
This simplifies to:
x2+2x3=0 x^2 + 2x - 3 = 0

Step 2: Identify the coefficients in the standard form ax2+bx+c=0 ax^2 + bx + c = 0 :
Here, a=1 a = 1 , b=2 b = 2 , and c=3 c = -3 .

Step 3: Use the quadratic formula:
x=b±b24ac2a x = \frac{{-b \pm \sqrt{{b^2 - 4ac}}}}{2a}

Plug in the values for a a , b b , and c c :
x=2±(2)24×1×(3)2×1 x = \frac{{-2 \pm \sqrt{{(2)^2 - 4 \times 1 \times (-3)}}}}{2 \times 1}

Simplify under the square root:
x=2±4+122=2±162 x = \frac{{-2 \pm \sqrt{{4 + 12}}}}{2} = \frac{{-2 \pm \sqrt{16}}}{2}

Simplify further:
x=2±42 x = \frac{{-2 \pm 4}}{2}

This results in two solutions:
For the positive square root:
x=2+42=22=1 x = \frac{{-2 + 4}}{2} = \frac{2}{2} = 1

For the negative square root:
x=242=62=3 x = \frac{{-2 - 4}}{2} = \frac{-6}{2} = -3

Therefore, the solutions are x1=1 x_1 = 1 , x2=3 x_2 = -3 .

Since these solutions match choice x1=1 x_1 = 1 , x2=3 x_2 = -3 , we verify accuracy against the answer choices.

The correct solution to the equation is x1=1 x_1 = 1 and x2=3 x_2 = -3 .

Answer

x1=1 x_1=1 , x2=3 x_2=-3

Exercise #2

What is the value of x?

x4x3=2x2 x^4-x^3=2x^2

Video Solution

Step-by-Step Solution

To solve the problem x4x3=2x2 x^4 - x^3 = 2x^2 , let's proceed as follows:

  • Step 1: Set the equation to zero.
    x4x32x2=0 x^4 - x^3 - 2x^2 = 0
  • Step 2: Factor out the greatest common factor.
    The common factor among all terms is x2 x^2 .
    Factoring out x2 x^2 gives:
    x2(x2x2)=0 x^2(x^2 - x - 2) = 0
  • Step 3: Solve the factors.
    This equation breaks into two factors that can be solved separately:
    • x2=0 x^2 = 0
    • x2x2=0 x^2 - x - 2 = 0
  • Step 4: Solve x2=0 x^2 = 0 .
    Since x2=0 x^2 = 0 , we get:
    x=0 x = 0
  • Step 5: Solve x2x2=0 x^2 - x - 2 = 0 .
    This can be factored further. We look for two numbers that multiply to 2-2 and add up to 1-1.
    These numbers are 2-2 and 11, so we factor as:
    (x2)(x+1)=0 (x - 2)(x + 1) = 0
  • Step 6: Solve the quadratic factors.
    Set each factor equal to zero:
    • x2=0x=2 x - 2 = 0 \Rightarrow x = 2
    • x+1=0x=1 x + 1 = 0 \Rightarrow x = -1

The solutions to the equation x4x3=2x2 x^4 - x^3 = 2x^2 are x=1,0,2 x = -1, 0, 2 .

Therefore, the correct answer is:

x=1,2,0 x = -1, 2, 0

Answer

x=1,2,0 x=-1,2,0

Exercise #3

Solve the following equation:

3x217x+28=x+4 3x^2-17x+28=x+4

Video Solution

Step-by-Step Solution

To solve the equation 3x217x+28=x+4 3x^2 - 17x + 28 = x + 4 , follow these steps:

  • Step 1: Simplify the equation.
    Begin by moving all terms to one side of the equation to obtain a standard form quadratic equation:
    3x217x+28x4=0 3x^2 - 17x + 28 - x - 4 = 0
  • Simplify further:
    3x218x+24=0 3x^2 - 18x + 24 = 0
  • Step 2: Identify coefficients.
    The equation is now in the standard form ax2+bx+c=0 ax^2 + bx + c = 0 where a=3 a = 3 , b=18 b = -18 , and c=24 c = 24 .
  • Step 3: Use the quadratic formula to solve for x x .
    The quadratic formula is given by:
    x=b±b24ac2a x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}
  • Calculate the discriminant b24ac b^2 - 4ac :
    (18)24(3)(24)=324288=36 (-18)^2 - 4(3)(24) = 324 - 288 = 36
  • Since the discriminant is positive, there are two solutions.
  • Apply the quadratic formula:
    x=(18)±362(3)=18±66 x = \frac{-(-18) \pm \sqrt{36}}{2(3)} = \frac{18 \pm 6}{6}
  • Calculate the two possible solutions:
    x1=18+66=4 x_1 = \frac{18 + 6}{6} = 4
    x2=1866=2 x_2 = \frac{18 - 6}{6} = 2

Therefore, the solutions to the equation are x1=4 x_1 = 4 and x2=2 x_2 = 2 .

Answer

x1=4 x_1=4 , x2=2 x_2=2

Exercise #4

Solve the following equation:

4x2+9x5=74x 4x^2+9x-5=7-4x

Video Solution

Step-by-Step Solution

Let's solve the equation 4x2+9x5=74x 4x^2 + 9x - 5 = 7 - 4x step by step:

  • Step 1: Move all terms to one side to form a standard quadratic equation.

We begin by subtracting 7 7 and adding 4x 4x to both sides of the given equation:

4x2+9x57+4x=0 4x^2 + 9x - 5 - 7 + 4x = 0

Combining like terms, we get:

4x2+13x12=0 4x^2 + 13x - 12 = 0

  • Step 2: Identify the coefficients a a , b b , and c c in the quadratic equation 4x2+13x12=0 4x^2 + 13x - 12 = 0 .

Here, a=4 a = 4 , b=13 b = 13 , and c=12 c = -12 .

  • Step 3: Apply the quadratic formula:

The quadratic formula is given by x=b±b24ac2a x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} .

Plugging in the values of a a , b b , and c c :

x=13±1324×4×(12)2×4 x = \frac{-13 \pm \sqrt{13^2 - 4 \times 4 \times (-12)}}{2 \times 4}

x=13±169+1928 x = \frac{-13 \pm \sqrt{169 + 192}}{8}

x=13±3618 x = \frac{-13 \pm \sqrt{361}}{8}

x=13±198 x = \frac{-13 \pm 19}{8}

  • Step 4: Solve for the possible values of x x .

We have two solutions:

For the positive case:

x1=13+198=68=34 x_1 = \frac{-13 + 19}{8} = \frac{6}{8} = \frac{3}{4}

For the negative case:

x2=13198=328=4 x_2 = \frac{-13 - 19}{8} = \frac{-32}{8} = -4

Therefore, the solutions are x1=34 x_1 = \frac{3}{4} and x2=4 x_2 = -4 .

Answer

x1=34 x_1=\frac{3}{4} x2=4 x_2=-4

Exercise #5

Find X

(3x+1)2+8=12 (3x+1)^2+8=12

Video Solution

Step-by-Step Solution

To solve the equation (3x+1)2+8=12(3x + 1)^2 + 8 = 12, we start by isolating the squared expression:

  • First, subtract 8 from both sides to simplify: (3x+1)2=128(3x + 1)^2 = 12 - 8.
  • This gives (3x+1)2=4(3x + 1)^2 = 4.

Next, we take the square root of both sides to remove the square:

  • 3x+1=±23x + 1 = \pm 2, recognizing the positive and negative roots of 4.

We now solve for xx in each case:

  • Case 1: 3x+1=23x + 1 = 2
    Subtract 1 from both sides: 3x=13x = 1
    Divide by 3: x=13x = \frac{1}{3}.
  • Case 2: 3x+1=23x + 1 = -2
    Subtract 1 from both sides: 3x=33x = -3
    Divide by 3: x=1x = -1.

Therefore, the solutions to the original equation are x1=13x_1 = \frac{1}{3} and x2=1x_2 = -1.

Answer

x1=13,x2=1 x_1=\frac{1}{3},x_2=-1

Exercise #6

x3=x2+2x x^3=x^2+2x

Video Solution

Step-by-Step Solution

To solve the problem x3=x2+2x x^3 = x^2 + 2x , follow these steps:

  • Step 1: Re-arrange the equation to have all terms on one side:
    x3x22x=0 x^3 - x^2 - 2x = 0 .
  • Step 2: Factor out the greatest common factor (GCF), which is x x :
    x(x2x2)=0 x(x^2 - x - 2) = 0 .
  • Step 3: Factor the quadratic expression x2x2 x^2 - x - 2 :
    The factors of 2-2 that add up to 1-1 are 2-2 and 11. Thus, x2x2=(x2)(x+1) x^2 - x - 2 = (x-2)(x+1) .
  • Step 4: Combine the factored terms:
    x(x2)(x+1)=0 x(x-2)(x+1) = 0 .

Each factor can be set to zero to find the solutions:

  • x=0 x = 0 .
  • x2=0 x - 2 = 0 , so x=2 x = 2 .
  • x+1=0 x + 1 = 0 , so x=1 x = -1 .

The solutions to the equation are x=0,1,2 x = 0, -1, 2 .

Therefore, the correct choice from the given options is:
x=0,1,2 x = 0, -1, 2 .

Answer

x=0,1,2 x=0,-1,2

Exercise #7

Solve the following equation:

10x265x+135=4x2+13x45 10x^2-65x+135=4x^2+13x-45

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Simplify the equation by gathering all terms on one side.
  • Step 2: Combine like terms to express the equation in standard quadratic form.
  • Step 3: Apply the quadratic formula to find the values of xx.

Now, let's work through each step:

Step 1: Starting with the equation 10x265x+135=4x2+13x4510x^2 - 65x + 135 = 4x^2 + 13x - 45, subtract 4x24x^2, 13x13x, and add 4545 on both sides:

10x265x+1354x213x+45=010x^2 - 65x + 135 - 4x^2 - 13x + 45 = 0

Step 2: Combine like terms:

(10x24x2)+(65x13x)+(135+45)=0(10x^2 - 4x^2) + (-65x - 13x) + (135 + 45) = 0

This simplifies to 6x278x+180=06x^2 - 78x + 180 = 0.

Step 3: Identify the coefficients a=6a = 6, b=78b = -78, and c=180c = 180. Use the quadratic formula:

x=b±b24ac2ax = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}

Substitute the values:

x=(78)±(78)24618026x = \frac{-(-78) \pm \sqrt{(-78)^2 - 4 \cdot 6 \cdot 180}}{2 \cdot 6}

x=78±6084432012x = \frac{78 \pm \sqrt{6084 - 4320}}{12}

x=78±176412x = \frac{78 \pm \sqrt{1764}}{12}

x=78±4212x = \frac{78 \pm 42}{12}

Calculating the two possible values:

x1=78+4212=12012=10x_1 = \frac{78 + 42}{12} = \frac{120}{12} = 10

x2=784212=3612=3x_2 = \frac{78 - 42}{12} = \frac{36}{12} = 3

Therefore, the solutions to the equation are x1=10x_1 = 10 and x2=3x_2 = 3.

The correct answer according to the provided choices is x1=10x_1=10 and x2=3x_2=3, which corresponds to choice 4.

Answer

x1=10 x_1=10 x2=3 x_2=3

Exercise #8

Solve the following equation:

2x2+6x12=4x2+19x5 -2x^2+6x-12=-4x^2+19x-5

Video Solution

Step-by-Step Solution

To solve this quadratic equation, let us first simplify and rearrange the terms:

Start with the original equation:
2x2+6x12=4x2+19x5-2x^2 + 6x - 12 = -4x^2 + 19x - 5

Move all terms to one side to form a standard quadratic equation by adding 4x24x^2, subtracting 19x19x, and adding 55 to both sides:

(2x2+6x12)+4x219x+5=0(-2x^2 + 6x - 12) + 4x^2 - 19x + 5 = 0

This simplifies to:
2x213x7=02x^2 - 13x - 7 = 0

Now, identify the coefficients a=2a = 2, b=13b = -13, and c=7c = -7.

Apply the quadratic formula:
x=b±b24ac2ax = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}

Subsitute aa, bb, and cc into the formula:

x=(13)±(13)242(7)22x = \frac{-(-13) \pm \sqrt{(-13)^2 - 4 \cdot 2 \cdot (-7)}}{2 \cdot 2}

Simplify:
x=13±169+564x = \frac{13 \pm \sqrt{169 + 56}}{4}

x=13±2254x = \frac{13 \pm \sqrt{225}}{4}

The square root of 225 is 15, thus:

x=13±154x = \frac{13 \pm 15}{4}

Calculate the two possible solutions:

  • First solution: x1=13+154=284=7x_1 = \frac{13 + 15}{4} = \frac{28}{4} = 7
  • Second solution: x2=13154=24=12x_2 = \frac{13 - 15}{4} = \frac{-2}{4} = -\frac{1}{2}

Therefore, the solutions to the problem are x1=7x_1 = 7 and x2=12x_2 = -\frac{1}{2}.

Thus, the correct answer is option 2: x1=7x_1=7, x2=12x_2=-\frac{1}{2}.

Answer

x1=7 x_1=7 , x2=12 x_2=-\frac{1}{2}

Exercise #9

Find X

7x+1+(2x+3)2=(4x+2)2 7x+1+(2x+3)^2=(4x+2)^2

Video Solution

Step-by-Step Solution

To solve the equation 7x+1+(2x+3)2=(4x+2)2 7x + 1 + (2x + 3)^2 = (4x + 2)^2 , we follow these steps:

  • Step 1: Expand both sides using the square of a binomial formula.
  • Step 2: Simplify the equation to form a standard quadratic equation.
  • Step 3: Use the quadratic formula to find the roots of the equation.

Step 1: Expand the squares.

The left side: (2x+3)2=4x2+12x+9 (2x + 3)^2 = 4x^2 + 12x + 9 .

The right side: (4x+2)2=16x2+16x+4 (4x + 2)^2 = 16x^2 + 16x + 4 .

Step 2: Substitute back into the original equation and simplify:

7x+1+4x2+12x+9=16x2+16x+4 7x + 1 + 4x^2 + 12x + 9 = 16x^2 + 16x + 4 .

Combine like terms:

4x2+19x+10=16x2+16x+4 4x^2 + 19x + 10 = 16x^2 + 16x + 4 .

Step 3: Move all terms to one side:

4x2+19x+1016x216x4=0 4x^2 + 19x + 10 - 16x^2 - 16x - 4 = 0 .

Which simplifies to:

12x2+3x+6=0-12x^2 + 3x + 6 = 0 .

Step 4: Divide by -3 to simplify:

4x2x2=0 4x^2 - x - 2 = 0 .

Step 5: Use the quadratic formula:

x=b±b24ac2a x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} , where a=4 a = 4 , b=1 b = -1 , c=2 c = -2 .

Calculate the discriminant:

b24ac=(1)244(2)=1+32=33 b^2 - 4ac = (-1)^2 - 4 \cdot 4 \cdot (-2) = 1 + 32 = 33 .

Calculate the roots:

x=1±338 x = \frac{1 \pm \sqrt{33}}{8} .

Therefore, the solution to the problem is x=1±338 x = \frac{1 \pm \sqrt{33}}{8} .

Answer

1±338 \frac{1\pm\sqrt{33}}{8}

Exercise #10

Given the equation. Find its solution

13x2+4x=8(x+3)2 13x^2+4x=8(x+3)^2

Video Solution

Step-by-Step Solution

To solve the equation 13x2+4x=8(x+3)2 13x^2 + 4x = 8(x+3)^2 , we proceed with the following steps:

  • **Step 1: Expand the right-hand side.**
    We start by expanding 8(x+3)2 8(x+3)^2 :
    (x+3)2=x2+6x+9(x+3)^2 = x^2 + 6x + 9
    Multiplying by 8 gives 8(x2+6x+9)=8x2+48x+72 8(x^2 + 6x + 9) = 8x^2 + 48x + 72 .
  • **Step 2: Form the standard quadratic equation.**
    Now substitute back into the initial equation:
    13x2+4x=8x2+48x+72 13x^2 + 4x = 8x^2 + 48x + 72
    Rearrange all terms to one side:
    13x2+4x8x248x72=0 13x^2 + 4x - 8x^2 - 48x - 72 = 0
    Simplify: 5x244x72=0 5x^2 - 44x - 72 = 0 .
  • **Step 3: Apply the quadratic formula.**
    The equation is in the standard form ax2+bx+c=0 ax^2 + bx + c = 0 where a=5 a = 5 , b=44 b = -44 , and c=72 c = -72 .
    Using the quadratic formula x=b±b24ac2a x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} , we calculate:
    x=(44)±(44)24×5×(72)2×5 x = \frac{-(-44) \pm \sqrt{(-44)^2 - 4 \times 5 \times (-72)}}{2 \times 5}
    x=44±1936+144010 x = \frac{44 \pm \sqrt{1936 + 1440}}{10}
    x=44±337610 x = \frac{44 \pm \sqrt{3376}}{10}
    337658.1 \sqrt{3376} \approx 58.1 , so:
    x=44±58.110 x = \frac{44 \pm 58.1}{10} .
  • **Step 4: Calculate the roots.**
    For the positive solution:
    x1=44+58.110=10.21 x_1 = \frac{44 + 58.1}{10} = 10.21 .
    For the negative solution:
    x2=4458.110=1.41 x_2 = \frac{44 - 58.1}{10} = -1.41 .

Therefore, the solutions to the equation are x1=10.21 x_1 = 10.21 and x2=1.41 x_2 = -1.41 . The correct choice from the given options is choice 3.

Answer

x1=10.21,x2=1.41 x_1=10.21,x_2=-1.41

Exercise #11

Given the following equation, find its solution

7x2+3x+8=9x+3 7x^2+3x+8=9x+3

Video Solution

Step-by-Step Solution

To solve the equation 7x2+3x+8=9x+3 7x^2 + 3x + 8 = 9x + 3 , follow these steps:

  • Step 1: Rearrange the equation into standard quadratic form:
    Move all terms to one side:
    7x2+3x+89x3=0 7x^2 + 3x + 8 - 9x - 3 = 0 .
  • Step 2: Simplify the equation:
    Combine like terms:
    7x26x+5=0 7x^2 - 6x + 5 = 0 .
  • Step 3: Identify coefficients:
    a=7 a = 7 , b=6 b = -6 , and c=5 c = 5 .
  • Step 4: Calculate the discriminant (Δ \Delta ):
    Δ=b24ac=(6)24(7)(5)=36140=104 \Delta = b^2 - 4ac = (-6)^2 - 4(7)(5) = 36 - 140 = -104 .
  • Step 5: Determine the nature of the roots:
    Since the discriminant is negative (Δ=104 \Delta = -104 ), this means there are no real solutions.

Therefore, the solution to the equation is No solution.

Answer

No solution

Exercise #12

Solve the following equation:

x2+x2=2x22x4 -x^2+x-2=-2x^2-2x-4

Video Solution

Step-by-Step Solution

To solve the equation x2+x2=2x22x4 -x^2 + x - 2 = -2x^2 - 2x - 4 , we will proceed with the following steps:

  • Step 1: Simplify the equation by moving all terms to one side of the equation.
  • Step 2: Combine like terms to form a quadratic equation.
  • Step 3: Use the quadratic formula to solve for x x .

Now, let's go through these steps:

Step 1: Start with the given equation:

x2+x2=2x22x4 -x^2 + x - 2 = -2x^2 - 2x - 4

Add 2x2 2x^2 , 2x 2x , and 4 4 to both sides to move all terms to the left side:

x2+x2+2x2+2x+4=0 -x^2 + x - 2 + 2x^2 + 2x + 4 = 0

Step 2: Combine like terms:

(2x2x2)+(x+2x)+(2+4)=0 (2x^2 - x^2) + (x + 2x) + (-2 + 4) = 0

This simplifies to:

x2+3x+2=0 x^2 + 3x + 2 = 0

Step 3: Use the quadratic formula (x=b±b24ac2a)(x = \frac{{-b \pm \sqrt{{b^2 - 4ac}}}}{2a}) with a=1 a = 1 , b=3 b = 3 , and c=2 c = 2 .

Calculate the discriminant: b24ac=32412=98=1 b^2 - 4ac = 3^2 - 4 \cdot 1 \cdot 2 = 9 - 8 = 1 .

Since the discriminant is positive, there are two distinct real roots. Substitute into the quadratic formula:

x=3±121=3±12 x = \frac{{-3 \pm \sqrt{1}}}{2 \cdot 1} = \frac{{-3 \pm 1}}{2}

Calculate the roots:

x1=3+12=22=1 x_1 = \frac{{-3 + 1}}{2} = \frac{{-2}}{2} = -1

x2=312=42=2 x_2 = \frac{{-3 - 1}}{2} = \frac{{-4}}{2} = -2

Therefore, the solutions to the equation are x1=2 x_1 = -2 and x2=1 x_2 = -1 .

Answer

x1=2,x2=1 x_1=-2,x_2=-1

Exercise #13

Solve the following equation:

x2+3x4=2x2 x^2+3x-4=2x^2

Video Solution

Step-by-Step Solution

Given the equation:

x2+3x4=2x2 x^2 + 3x - 4 = 2x^2

Step 1: Move all terms to one side:

Subtract 2x2 2x^2 from both sides to get:

x2+3x42x2=0 x^2 + 3x - 4 - 2x^2 = 0

Simplify this to:

x2+3x4=0-x^2 + 3x - 4 = 0

Step 2: Rearrange to standard form:

Multiply the entire equation by -1 for simplicity:

x23x+4=0 x^2 - 3x + 4 = 0

Step 3: Solve the quadratic equation using the quadratic formula:

Here, a=1 a = 1 , b=3 b = -3 , c=4 c = 4 .

Plug into the quadratic formula:

x=(3)±(3)24×1×42×1 x = \frac{-(-3) \pm \sqrt{(-3)^2 - 4 \times 1 \times 4}}{2 \times 1}

x=3±9162 x = \frac{3 \pm \sqrt{9 - 16}}{2}

x=3±72 x = \frac{3 \pm \sqrt{-7}}{2}

Step 4: Interpret the result:

The discriminant (b24ac b^2 - 4ac ) is negative, 7 -7 , indicating no real solutions.

Conclusion: The equation has no solution in the set of real numbers.

In comparison with the provided choices, the correct choice is:

No solution

Answer

No solution

Exercise #14

Solve the following equation:

x3+1(x1)2=x+4 \frac{x^3+1}{(x-1)^2}=x+4

Video Solution

Step-by-Step Solution

To solve this equation, we follow these steps:

  • Step 1: Multiply both sides by (x1)2(x-1)^2 to eliminate the fraction.
  • Step 2: Expand and simplify both sides of the equation.
  • Step 3: Rearrange the equation to form a polynomial equal to zero.
  • Step 4: Solve the resulting polynomial using factorization or the quadratic formula.

Now, let's execute these steps:

Step 1: Multiply both sides by (x1)2(x-1)^2:
(x3+1)=(x+4)(x1)2(x^3 + 1) = (x + 4)(x - 1)^2

Step 2: Expand the right side:
(x+4)(x22x+1)=x(x22x+1)+4(x22x+1) (x + 4)(x^2 - 2x + 1) = x(x^2 - 2x + 1) + 4(x^2 - 2x + 1)

Calculating each part yields:
x(x22x+1)=x32x2+x x(x^2 - 2x + 1) = x^3 - 2x^2 + x
4(x22x+1)=4x28x+4 4(x^2 - 2x + 1) = 4x^2 - 8x + 4

Add these together:
x32x2+x+4x28x+4=x3+2x27x+4 x^3 - 2x^2 + x + 4x^2 - 8x + 4 = x^3 + 2x^2 - 7x + 4

Step 3: Combine terms and rearrange:
x3+1=x3+2x27x+4 x^3 + 1 = x^3 + 2x^2 - 7x + 4

Simplify by cancelling x3x^3 from both sides:
1=2x27x+4 1 = 2x^2 - 7x + 4

Move 1 to the right side:
0=2x27x+3 0 = 2x^2 - 7x + 3

Step 4: Solve the quadratic equation 2x27x+3=0 2x^2 - 7x + 3 = 0 .

Using the quadratic formula, x=b±b24ac2a x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} , where a=2 a = 2 , b=7 b = -7 , and c=3 c = 3 .

Calculate the discriminant:
b24ac=(7)2423=4924=25 b^2 - 4ac = (-7)^2 - 4 \cdot 2 \cdot 3 = 49 - 24 = 25

Now plug into the quadratic formula:
x=7±254 x = \frac{7 \pm \sqrt{25}}{4}

Simplify:
x=7±54 x = \frac{7 \pm 5}{4}

Two solutions arise:
x=124=3 x = \frac{12}{4} = 3 and x=24=12 x = \frac{2}{4} = \frac{1}{2}

Since x=1 x = 1 would make the denominator zero, it is not a valid solution for the original equation.

Therefore, the solution to the problem is x=3 x = 3 or x=12 x = \frac{1}{2} .

Answer

x=3,12 x=3,\frac{1}{2}

Exercise #15

Solve the following equation:

(x+3)2=4x -(x+3)^2=4x

Video Solution

Step-by-Step Solution

To solve (x+3)2=4x -(x+3)^2 = 4x , follow these steps:

  • Step 1: Expand the left side: (x+3)2=(x2+6x+9) -(x+3)^2 = -(x^2 + 6x + 9) .
  • Step 2: Distribute the negative sign: x26x9 -x^2 - 6x - 9 .
  • Step 3: Set the equation by moving terms to the right: x26x9=4x -x^2 - 6x - 9 = 4x becomes x26x94x=0 -x^2 - 6x - 9 - 4x = 0 .
  • Step 4: Simplify to standard quadratic form: x210x9=0 -x^2 - 10x - 9 = 0 .
  • Step 5: Applying the quadratic formula where a=1 a = -1 , b=10 b = -10 , c=9 c = -9 :
  • x=(10)±(10)24(1)(9)2(1) x = \frac{-(-10) \pm \sqrt{(-10)^2 - 4 \cdot (-1) \cdot (-9)}}{2 \cdot (-1)} .
  • x=10±100362 x = \frac{10 \pm \sqrt{100 - 36}}{-2} .
  • x=10±642 x = \frac{10 \pm \sqrt{64}}{-2} .
  • x=10±82 x = \frac{10 \pm 8}{-2} .
  • Two solutions arise: x=10+82=9 x = \frac{10 + 8}{-2} = -9 and x=1082=1 x = \frac{10 - 8}{-2} = -1 .

Therefore, the solutions are x1=1 x_1 = -1 and x2=9 x_2 = -9 .

Thus, the correct answer is x1=1,x2=9\mathbf{x_1=-1,x_2=-9}.

Answer

x1=1,x2=9 x_1=-1,x_2=-9

Exercise #16

Solve the following equation:

(x+2)2=(2x+3)2 (x+2)^2=(2x+3)^2

Video Solution

Step-by-Step Solution

We will solve the equation (x+2)2=(2x+3)2 (x+2)^2 = (2x+3)^2 by expanding and simplifying both sides:

Step 1: Expand both sides of the equation:
Left side: (x+2)2=x2+4x+4 (x+2)^2 = x^2 + 4x + 4
Right side: (2x+3)2=4x2+12x+9 (2x+3)^2 = 4x^2 + 12x + 9

Step 2: Set the expanded forms equal to each other:
x2+4x+4=4x2+12x+9 x^2 + 4x + 4 = 4x^2 + 12x + 9

Step 3: Rearrange to form a standard quadratic equation:
Subtract x2+4x+4 x^2 + 4x + 4 from both sides:
0=3x2+8x+5 0 = 3x^2 + 8x + 5

Step 4: Rearrange to get:
3x2+8x+5=0 3x^2 + 8x + 5 = 0

Step 5: Solve using the quadratic formula:
Using a=3 a = 3 , b=8 b = 8 , c=5 c = 5 :
x=b±b24ac2a x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}
x=8±8243523 x = \frac{-8 \pm \sqrt{8^2 - 4 \cdot 3 \cdot 5}}{2 \cdot 3}
x=8±64606 x = \frac{-8 \pm \sqrt{64 - 60}}{6}
x=8±46 x = \frac{-8 \pm \sqrt{4}}{6}
x=8±26 x = \frac{-8 \pm 2}{6}

Step 6: Calculate the solutions:
x1=8+26=66=1 x_1 = \frac{-8 + 2}{6} = \frac{-6}{6} = -1
x2=826=106=53 x_2 = \frac{-8 - 2}{6} = \frac{-10}{6} = -\frac{5}{3}

Verify in the original equation to assure correctness. Hence, both solutions are valid.

Therefore, the solutions are x1=1 x_1 = -1 and x2=53 x_2 = -\frac{5}{3} , which matches choice 3.

Answer

x1=1,x2=53 x_1=-1,x_2=-\frac{5}{3}

Exercise #17

Solve the following equation:

(x4)2+3x2=16x+12 (x-4)^2+3x^2=-16x+12

Video Solution

Step-by-Step Solution

To solve the given equation, follow these steps:

  • Step 1: Expand (x4)2(x - 4)^2 using the formula (ab)2=a22ab+b2(a - b)^2 = a^2 - 2ab + b^2.

Thus, (x4)2=x28x+16(x - 4)^2 = x^2 - 8x + 16.

  • Step 2: Substitute the expanded form into the equation:

x28x+16+3x2=16x+12x^2 - 8x + 16 + 3x^2 = -16x + 12.

  • Step 3: Combine like terms on the left-hand side.

This gives 4x28x+16=16x+124x^2 - 8x + 16 = -16x + 12.

  • Step 4: Rearrange the equation to set it to zero.

Bring all terms to one side: 4x28x+16+16x12=04x^2 - 8x + 16 + 16x - 12 = 0.

Combine and simplify the terms: 4x2+8x+4=04x^2 + 8x + 4 = 0.

  • Step 5: Simplify the equation by dividing each term by 4.

It becomes x2+2x+1=0x^2 + 2x + 1 = 0.

  • Step 6: Recognize the equation as a perfect square trinomial.

(x+1)2=0(x + 1)^2 = 0.

  • Step 7: Solve by taking the square root of both sides.

The solution is x+1=0x + 1 = 0, therefore x=1x = -1.

In conclusion, the solution to the equation is x=1 x = -1 .

Answer

x=1 x=-1

Exercise #18

Solve the following equation:

(x5)25=12+2x (x-5)^2-5=-12+2x

Video Solution

Step-by-Step Solution

To solve the equation (x5)25=12+2x(x-5)^2 - 5 = -12 + 2x, follow these steps:

  • Step 1: Expand the square on the left side of the equation:
    (x5)2=x210x+25(x-5)^2 = x^2 - 10x + 25
  • Step 2: Substitute this back into the equation:
    x210x+255=12+2xx^2 - 10x + 25 - 5 = -12 + 2x
  • Step 3: Simplify the equation:
    x210x+20=12+2xx^2 - 10x + 20 = -12 + 2x
  • Step 4: Rearrange the equation by moving all terms to one side:
    x210x+202x+12=0x^2 - 10x + 20 - 2x + 12 = 0
    This simplifies to x212x+32=0x^2 - 12x + 32 = 0.
  • Step 5: Use the Quadratic Formula, where a=1a = 1, b=12b = -12, and c=32c = 32:
    x=(12)±(12)24×1×322×1x = \frac{-(-12) \pm \sqrt{(-12)^2 - 4 \times 1 \times 32}}{2 \times 1}
  • Step 6: Calculate the discriminant and simplify:
    x=12±1441282x = \frac{12 \pm \sqrt{144 - 128}}{2}
    x=12±162x = \frac{12 \pm \sqrt{16}}{2}
    x=12±42x = \frac{12 \pm 4}{2}
  • Step 7: Solve for the two potential values of xx:
    x1=12+42=8x_1 = \frac{12 + 4}{2} = 8
    x2=1242=4x_2 = \frac{12 - 4}{2} = 4

Thus, the solutions to the equation are x1=8x_1 = 8 and x2=4x_2 = 4.

Therefore, the correct answer is x1=8,x2=4x_1 = 8, x_2 = 4, which corresponds to choice 1.

Answer

x1=8,x2=4 x_1=8,x_2=4

Exercise #19

Solve the following equation:

(x+3)2=2x+5 (x+3)^2=2x+5

Video Solution

Step-by-Step Solution

To solve the equation (x+3)2=2x+5 (x+3)^2 = 2x + 5 , we proceed as follows:

  • Step 1: Expand the left side. Using the identity (a+b)2=a2+2ab+b2 (a+b)^2 = a^2 + 2ab + b^2 , we find:
    (x+3)2=x2+6x+9 (x+3)^2 = x^2 + 6x + 9 .

  • Step 2: Set the equation to zero by moving all terms to one side:
    x2+6x+9=2x+5 x^2 + 6x + 9 = 2x + 5
    Subtract 2x+5 2x + 5 from both sides:
    x2+6x+92x5=0 x^2 + 6x + 9 - 2x - 5 = 0
    This simplifies to:
    x2+4x+4=0 x^2 + 4x + 4 = 0 .

  • Step 3: Solve the quadratic equation x2+4x+4=0 x^2 + 4x + 4 = 0 . Notice this can be factored as:
    (x+2)2=0 (x+2)^2 = 0 .

  • Step 4: Solve for x x by setting the factor equal to zero:
    x+2=0 x+2 = 0 .
    Thus, x=2 x = -2 .

Therefore, the solution to the equation (x+3)2=2x+5 (x+3)^2 = 2x + 5 is x=2 x = -2 .

Answer

x=2 x=-2

Exercise #20

Solve the equation

2x22x=(x+1)2 2x^2-2x=(x+1)^2

Video Solution

Step-by-Step Solution

The given equation is:

2x22x=(x+1)2 2x^2 - 2x = (x+1)^2

Step 1: Expand the right-hand side.

(x+1)2=x2+2x+1(x+1)^2 = x^2 + 2x + 1

Step 2: Write the full equation with the expanded form.

2x22x=x2+2x+12x^2 - 2x = x^2 + 2x + 1

Step 3: Bring all terms to one side of the equation to set it to zero.

2x22xx22x1=02x^2 - 2x - x^2 - 2x - 1 = 0

Step 4: Simplify the equation.

x24x1=0x^2 - 4x - 1 = 0

Step 5: Identify coefficients for the quadratic formula.

Here, a=1a = 1, b=4b = -4, c=1c = -1.

Step 6: Apply the quadratic formula.

x=(4)±(4)241(1)21x = \frac{-(-4) \pm \sqrt{(-4)^2 - 4 \cdot 1 \cdot (-1)}}{2 \cdot 1}

x=4±16+42x = \frac{4 \pm \sqrt{16 + 4}}{2}

x=4±202x = \frac{4 \pm \sqrt{20}}{2}

x=4±252x = \frac{4 \pm 2\sqrt{5}}{2}

x=2±5x = 2 \pm \sqrt{5}

Therefore, the solutions are x=2+5x = 2 + \sqrt{5} and x=25x = 2 - \sqrt{5}.

These solutions correspond to choice (4): Answers a + b

Answer

Answers a + b