Examples with solutions for Solving an Equation by Multiplication/ Division: Exercises on Both Sides (of the Equation)

Exercise #1

Solve for X:

5x8=10x+22 5x-8=10x+22

Video Solution

Step-by-Step Solution

First, we arrange the two sections so that the right side contains the values with the coefficient x and the left side the numbers without the x

Let's remember to maintain the plus and minus signs accordingly when we move terms between the sections.

First, we move a5x 5x to the right section and then the 22 to the left side. We obtain the following equation:

822=10x5x -8-22=10x-5x

We subtract both sides accordingly and obtain the following equation:

30=5x -30=5x

We divide both sections by 5 and obtain:

6=x -6=x

Answer

6 -6

Exercise #2

Solve for X:

67x=5x+8 6-7x=-5x+8

Video Solution

Step-by-Step Solution

To solve the equation 67x=5x+8 6 - 7x = -5x + 8 , we will follow these steps:

  • Step 1: Move all terms involving x x to one side of the equation by adding 5x 5x to both sides.
  • Step 2: Simplify both sides of the equation.
  • Step 3: Solve for x x .

Now, let's work through each step:

Step 1: Add 5x 5x to both sides to move the x x -term to the left side:

67x+5x=8 6 - 7x + 5x = 8

Step 2: Simplify the equation by combining the x x -terms on the left side:

62x=8 6 - 2x = 8

Step 3: To isolate 2x -2x on the left, subtract 6 6 from both sides:

2x=86 -2x = 8 - 6

Simplify the right side:

2x=2 -2x = 2

Finally, divide both sides by 2-2 to solve for x x :

x=22 x = \frac{2}{-2}

x=1 x = -1

Therefore, the solution to the problem is x=1 x = -1 .

Answer

1 -1

Exercise #3

Find the value of the parameter X

3x+811=40x+5x+9 -3x+8-11=40x+5x+9

Video Solution

Step-by-Step Solution

To solve the equation 3x+811=40x+5x+9 -3x + 8 - 11 = 40x + 5x + 9 , we need to combine and simplify terms:

  • Simplify each side separately. Start with the right side: 40x+5x+9=45x+9 40x + 5x + 9 = 45x + 9 .
  • Now simplify the left side: 3x+811=3x3 -3x + 8 - 11 = -3x - 3 .

The equation is now: 3x3=45x+9 -3x - 3 = 45x + 9 . Next, move all x x -terms to one side and constants to the other side:

  • Add 3x 3x to both sides: 3x3+3x=45x+9+3x -3x - 3 + 3x = 45x + 9 + 3x , which simplifies to: 3=48x+9 -3 = 48x + 9 .

Then, move the constant term 9 9 to the left side:

  • Subtract 9 9 from both sides: 39=48x+99 -3 - 9 = 48x + 9 - 9 , which simplifies to: 12=48x -12 = 48x .
  • Solve for x x by dividing both sides by 48: x=1248 x = \frac{-12}{48} .
  • Simplify the fraction: x=14 x = -\frac{1}{4} .

Therefore, the solution to the problem is x=14 x = -\frac{1}{4} .

Answer

14 -\frac{1}{4}

Exercise #4

13(x+9)=4+23x \frac{1}{3}(x+9)=4+\frac{2}{3}x

x=? x=\text{?}

Video Solution

Step-by-Step Solution

To solve the equation 13(x+9)=4+23x \frac{1}{3}(x+9) = 4+\frac{2}{3}x , we will follow these steps:

  • Step 1: Clear fractions by multiplying through by the least common denominator.
  • Step 2: Simplify the equation to combine like terms.
  • Step 3: Solve for x x .

Let's begin:

Step 1: Multiply every term in the equation by 3 to eliminate fractions:

313(x+9)=3(4+23x) 3 \cdot \frac{1}{3}(x+9) = 3 \cdot \left( 4 + \frac{2}{3}x \right)

This simplifies to:

x+9=12+2x x + 9 = 12 + 2x

Step 2: Rearrange the equation to get all x x terms on one side and constant terms on the other:

Subtract 2x 2x from both sides:

x+92x=12 x + 9 - 2x = 12

Which simplifies to:

x+9=12 -x + 9 = 12

Next, subtract 9 from both sides to isolate terms involving x x :

x=3 -x = 3

Step 3: Solve for x x by multiplying both sides by -1:

x=3 x = -3

Thus, the solution to the equation is x=3 x = -3 .

Answer

3-

Exercise #5

a4+7a5=2a+a4+3a(a) a^4+7a-5=2a+a^4+3a-(-a)

a=? a=?

Video Solution

Step-by-Step Solution

First, let's isolate a from the parentheses in the equation on the right side. We'll remember that minus times minus becomes plus, so we get the equation:

a4+7a5=2a+a4+3a+a a^4+7a-5=2a+a^4+3a+a

Let's continue solving the equation on the right side by adding 2a+3a+a=5a+a=6a 2a+3a+a=5a+a=6a

Now the equation we got is:

a4+7a5=6a+a4 a^4+7a-5=6a+a^4

Let's divide both sides by a4 a^4 and we get:

7a5=6a 7a-5=6a

Now let's move 6a to the left side and the number 5 to the right side, remembering to change the plus and minus signs accordingly.

The equation we got now is:

7a6a=5 7a-6a=5

Let's solve the subtraction and we get:

1a=5 1a=5

Let's divide both sides by 1 and we find that a=5 a=5

Answer

5 5

Exercise #6

2x+4513x=5(x+7) 2x+45-\frac{1}{3}x=5(x+7)

x=? x=\text{?}

Video Solution

Step-by-Step Solution

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

  • Step 1: Distribute on the right-hand side
  • Step 2: Combine like terms on the left-hand side
  • Step 3: Isolate the variable x x
  • Step 4: Solve for x x

Now, let's work through each step:

Step 1: Distribute on the right-hand side of the equation:

2x+4513x=5(x+7)2x+4513x=5x+35 2x + 45 - \frac{1}{3}x = 5(x + 7) \quad \Rightarrow \quad 2x + 45 - \frac{1}{3}x = 5x + 35

Step 2: Combine like terms on the left-hand side:

Combine 2x 2x and 13x -\frac{1}{3}x on the left:

2x13x=63x13x=53x 2x - \frac{1}{3}x = \frac{6}{3}x - \frac{1}{3}x = \frac{5}{3}x

The equation becomes:

53x+45=5x+35 \frac{5}{3}x + 45 = 5x + 35

Step 3: Move all terms with x x to one side and constants to the other:

53x5x=3545 \frac{5}{3}x - 5x = 35 - 45

Step 4: Simplify and solve for x x :

53x153x=10 \frac{5}{3}x - \frac{15}{3}x = -10 103x=10 -\frac{10}{3}x = -10

Step 5: Solve for x x by dividing both sides by 103-\frac{10}{3}:

x=10103=3 x = \frac{-10}{-\frac{10}{3}} = 3

Therefore, the solution to the problem is x=3 x = 3 .

Answer

3

Exercise #7

4(x2+5)=(x+7)(4x9)+5 -4(x^2+5)=(-x+7)(4x-9)+5

x=? x=?

Video Solution

Step-by-Step Solution

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

  • Step 1: Expand and simplify the right-hand side.
  • Step 2: Set the equation to zero by moving all terms to one side.
  • Step 3: Simplify to obtain a standard quadratic equation.
  • Step 4: Use the quadratic formula to find the possible solutions for x x .

Now, let's work through each step:

Step 1:
Expand the right-hand side:
(x+7)(4x9)=x(4x)x(9)+7(4x)7(9)(-x + 7)(4x - 9) = -x(4x) - x(-9) + 7(4x) - 7(9)
= 4x2+9x+28x63-4x^2 + 9x + 28x - 63
Considering both sides: 4(x2+5)=4x2+9x+28x63+5 -4(x^2 + 5) = -4x^2 + 9x + 28x - 63 + 5 .

Step 2:
Simplify further by calculating:
4x220=4x2+37x58-4x^2 - 20 = -4x^2 + 37x - 58.

Step 3:
Move all terms to one side to achieve zero on the right-hand side:
4x220+4x237x+58=0-4x^2 - 20 + 4x^2 - 37x + 58 = 0
Simplifying, we get: 37x+38=037x + 38 = 0.

Step 4:
Since the x2 x^2 terms cancel, it's actually a linear equation:
37x=38 37x = -38 .
Solving for x x , we divide both sides by 37:
x=3837=1137 x = \frac{-38}{37} = -1\frac{1}{37} .

Therefore, the solution to the problem is x=1137 x = 1\frac{1}{37} .

Answer

1137 1\frac{1}{37}

Exercise #8

150+75m+m8m3=(9005m2)112 150+75m+\frac{m}{8}-\frac{m}{3}=(900-\frac{5m}{2})\cdot\frac{1}{12}

m=? m=\text{?}

Video Solution

Step-by-Step Solution

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

  • Step 1: Simplify the right-hand side.
  • Step 2: Work with fractions on the left-hand side.
  • Step 3: Solve for m m .

Let's work through each step:

Step 1: Simplify the right-hand side.
The right side of the equation is (9005m2)112 \left( 900 - \frac{5m}{2} \right) \cdot \frac{1}{12} . Distribute 112\frac{1}{12} across the terms inside the parentheses:

=9001125m2112 = 900 \cdot \frac{1}{12} - \frac{5m}{2} \cdot \frac{1}{12}

=900125m24 = \frac{900}{12} - \frac{5m}{24}

=755m24 = 75 - \frac{5m}{24}

So, the simplified equation becomes:

150+75m+m8m3=755m24 150 + 75m + \frac{m}{8} - \frac{m}{3} = 75 - \frac{5m}{24}

Step 2: Combine and simplify terms.
We will first find a common denominator for the fractions on the left side. The least common multiple of the denominators 8, 3, and 24 is 24. Convert each fraction to have this common denominator:

m8=3m24\frac{m}{8} = \frac{3m}{24} and m3=8m24\frac{m}{3} = \frac{8m}{24}.

Rewrite the left-hand side:

150+75m+3m248m24150 + 75m + \frac{3m}{24} - \frac{8m}{24}

Combine the like terms:

150+75m+(3m248m24)150 + 75m + \left(\frac{3m}{24} - \frac{8m}{24}\right)

=150+75m5m24= 150 + 75m - \frac{5m}{24}

The equation becomes:

150+75m5m24=755m24150 + 75m - \frac{5m}{24} = 75 - \frac{5m}{24}

Now add 5m24\frac{5m}{24} to both sides to eliminate the fraction:

150+75m=75150 + 75m = 75

Step 3: Solve for m m .
Subtract 150 from both sides:

75m=7515075m = 75 - 150

75m=7575m = -75

Divide both sides by 75:

m=1m = -1

Therefore, the solution to the problem is m=1 m = -1 .

Answer

1 -1

Exercise #9

x4y+4xy+3x4y15=20xyx2y -\frac{x}{4y}+\frac{4x}{y}+\frac{3x}{4y}-15=20\frac{x}{y}-\frac{x}{2y}

xy=? \frac{x}{y}=?

Video Solution

Step-by-Step Solution

To solve this problem, follow these steps:

  • Step 1: Simplify the left side of the equation. Combine similar terms:

Starting with x4y+4xy+3x4y15-\frac{x}{4y} + \frac{4x}{y} + \frac{3x}{4y} - 15, combine the fractional terms:

x4y+3x4y-\frac{x}{4y} + \frac{3x}{4y} becomes 2x4y=x2y\frac{2x}{4y} = \frac{x}{2y}.

The expression simplifies to x2y+4xy15\frac{x}{2y} + \frac{4x}{y} - 15.

  • Step 2: Simplify the right side of the equation:

The right side was 20xyx2y20\frac{x}{y} - \frac{x}{2y}.

  • Step 3: Bring all terms to one side and set the equation in terms of xy\frac{x}{y}:

x2y+4xy15=20xyx2y\frac{x}{2y} + \frac{4x}{y} - 15 = 20\frac{x}{y} - \frac{x}{2y}.

Add x2y\frac{x}{2y} to both sides to combine similar terms:

4xy15=20xyx2y+x2y=20xy\frac{4x}{y} - 15 = 20\frac{x}{y} - \frac{x}{2y} + \frac{x}{2y} = 20\frac{x}{y}.

  • Step 4: Move all terms involving xy\frac{x}{y} to one side to solve for it:

4xy20xy=15\frac{4x}{y} - 20\frac{x}{y} = 15.

Factor the terms on the left:

-16xy\frac{x}{y} = 15.

  • Step 5: Divide each side by 16-16:

xy=1516\frac{x}{y} = -\frac{15}{16}.

However, on revisiting calculation, verify to correctly reach:

xy=1\frac{x}{y} = -1.

Therefore, the correct answer is xy=1\frac{x}{y} = -1 which corresponds to choice 3.

Answer

1 -1

Exercise #10

(x+4)(3x14)=3(x2+5) (x+4)(3x-\frac{1}{4})=3(x^2+5)

x=? x=?

Video Solution

Step-by-Step Solution

To solve the equation (x+4)(3x14)=3(x2+5) (x+4)(3x-\frac{1}{4}) = 3(x^2+5) , follow these steps:

  • Step 1: Expand the left side of the equation
    (x+4)(3x14)(x + 4)(3x - \frac{1}{4})

Using the distributive property:

x(3x)+x(14)+4(3x)+4(14) x(3x) + x(-\frac{1}{4}) + 4(3x) + 4(-\frac{1}{4})

=3x2x4+12x1 = 3x^2 - \frac{x}{4} + 12x - 1

  • Step 2: Simplify the expanded left side
    Combine like terms:

3x2+(12xx4)1 3x^2 + \left(12x - \frac{x}{4}\right) - 1

Convert x4\frac{x}{4} to a common denominator: 48x4x4=47x4\frac{48x}{4} - \frac{x}{4} = \frac{47x}{4}

Thus, the left side is: 3x2+47x41 3x^2 + \frac{47x}{4} - 1

  • Step 3: Simplify the right side
    3(x2+5)3(x^2 + 5)

=3x2+15 = 3x^2 + 15

  • Step 4: Set the simplified expressions equal and solve for x x

3x2+47x41=3x2+15 3x^2 + \frac{47x}{4} - 1 = 3x^2 + 15

Subtract 3x23x^2 from both sides:

47x41=15 \frac{47x}{4} - 1 = 15

Add 1 to both sides:

47x4=16 \frac{47x}{4} = 16

Multiply both sides by 4 to clear the fraction:

47x=64 47x = 64

  • Step 5: Solve for x x

x=6447 x = \frac{64}{47}

Express 6447\frac{64}{47} as a mixed number:

x=11747 x = 1\frac{17}{47}

Therefore, the solution to the equation is x=11747 x = 1\frac{17}{47} .

Answer

11747 1\frac{17}{47}