Examples with solutions for Solving Equations Using All Methods: Solving an equation by multiplying/dividing both sides

Exercise #1

Solve for X:

5x=25 5x=25

Video Solution

Step-by-Step Solution

To solve the equation 5x=255x = 25, we will isolate xx using division:

  • Divide both sides of the equation by 5:
5x5=255 \frac{5x}{5} = \frac{25}{5}

After performing the division, we get:

x=5 x = 5

Thus, the solution to the equation is x=5 x = 5 .

Answer

5

Exercise #2

Solve for X:

13x=9 \frac{1}{3}x=9

Video Solution

Step-by-Step Solution

To solve the equation 13x=9\frac{1}{3}x = 9, we need to isolate the variable xx. To accomplish this, we can multiply both sides of the equation by 3, the reciprocal of 13\frac{1}{3}.

Step-by-step solution:

  • Step 1: Multiply both sides by 3.
    (3×13)x=3×9\left(3 \times \frac{1}{3}\right)x = 3 \times 9
  • Step 2: Simplify the left side.
    This gives us 1x=271x = 27, since (3×13)=1\left(3 \times \frac{1}{3}\right) = 1.
  • Step 3: Conclude that x=27x = 27.

Therefore, the solution to the equation is x=27 x = 27 . This matches choice number 1 from the provided options.

Answer

27

Exercise #3

Solve for X:

10+3x=19 10+3x=19

Video Solution

Step-by-Step Solution

To solve the equation 10+3x=1910 + 3x = 19, follow these steps:

  • Step 1: Subtract 10 from both sides of the equation to begin isolating xx:
  • 10+3x10=191010 + 3x - 10 = 19 - 10
  • This simplifies to 3x=93x = 9.
  • Step 2: Divide both sides by 3 to solve for xx:
  • 3x3=93\frac{3x}{3} = \frac{9}{3}
  • This reduces to x=3x = 3.

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

Answer

3

Exercise #4

Solve for X:

248x=2x 24-8x=-2x

Video Solution

Step-by-Step Solution

To solve the equation 248x=2x 24 - 8x = -2x , we need to isolate x x . Follow these steps:

  • Step 1: Move all terms involving x x to one side of the equation. Add 8x 8x to both sides to get:
    24=8x2x 24 = 8x - 2x
  • Step 2: Simplify the equation by combining like terms on the right:
    24=6x 24 = 6x
  • Step 3: Solve for x x by dividing both sides by 6:
    x=246 x = \frac{24}{6}
  • Step 4: Simplify the result:
    x=4 x = 4

Therefore, the solution to the problem is x=4 \mathbf{x = 4} .

Answer

4

Exercise #5

Solve for X:

33x11x=66 33x-11x=66

Video Solution

Step-by-Step Solution

To solve the given linear equation 33x11x=66 33x - 11x = 66 , we will follow these steps:

  • Simplify the equation by combining like terms.
  • Isolate the variable x x to find its value.

Here's how we approach it:

Step 1: Combine like terms on the left-hand side of the equation.

We have 33x11x 33x - 11x . By combining these terms, we calculate:

33x11x=(3311)x=22x 33x - 11x = (33 - 11)x = 22x .

Our equation now simplifies to 22x=66 22x = 66 .

Step 2: Isolate x x by dividing both sides of the equation by 22.

When we divide both sides of the equation by 22, we get:

x=6622 x = \frac{66}{22} .

By performing the division, we find x=3 x = 3 .

Therefore, the value of x x that satisfies the equation 33x11x=66 33x - 11x = 66 is x=3 x = 3 .

Answer

3

Exercise #6

Solve for X:

8x+3=29 -8x+3=-29

Video Solution

Step-by-Step Solution

To solve the equation 8x+3=29 -8x + 3 = -29 , we'll follow these steps:

  • Step 1: Subtract 3 from both sides of the equation to eliminate the constant on the left side.
  • Step 2: Divide both sides by 8-8, the coefficient of xx, to solve for xx.

Let's apply these steps:
Step 1: Subtract 3 from both sides:
8x+33=293-8x + 3 - 3 = -29 - 3
This simplifies to:
8x=32-8x = -32

Step 2: Divide both sides by 8-8 to isolate xx:
8x8=328\frac{-8x}{-8} = \frac{-32}{-8}
This results in:
x=4x = 4

Therefore, the solution to the equation is x=4 x = 4 , which corresponds to choice 4.

Answer

4

Exercise #7

Solve for X:

3x5=10 3x-5=10

Video Solution

Step-by-Step Solution

To solve the equation 3x5=103x - 5 = 10, we follow these steps:

  • Add 55 to both sides of the equation to eliminate the 5-5:
    3x5+5=10+53x - 5 + 5 = 10 + 5
    Simplifies to:
    3x=153x = 15
  • Next, divide both sides of the equation by 33 to solve for xx:
    3x3=153\frac{3x}{3} = \frac{15}{3}
    This results in:
    x=5x = 5

Therefore, the solution to the equation is x=5x = 5.

Answer

5

Exercise #8

Solve for X:

6x=72 6x=72

Video Solution

Step-by-Step Solution

To solve for xx in the equation 6x=726x = 72, follow these steps:

Step 1: Identify the equation and the coefficient of xx.
The given equation is 6x=726x = 72, where the coefficient of xx is 6.

Step 2: Isolate xx by dividing both sides of the equation by the coefficient (6).
Perform the division: x=726x = \frac{72}{6}.

Step 3: Simplify the result.
Calculating 726\frac{72}{6}, we get x=12x = 12.

Therefore, the solution to the equation is x=12x = 12.

Answer

12

Exercise #9

Solve for X:

15x=12 \frac{1}{5}x=12

Video Solution

Step-by-Step Solution

To solve this problem, we will follow the steps outlined below:

  • Step 1: Recognize that 15x=12 \frac{1}{5}x = 12 gives us x x multiplied by 15 \frac{1}{5} .
  • Step 2: Multiply both sides of the equation by 5 to eliminate the fraction.
  • Step 3: Simplify the resulting equation to solve for x x .

Let's proceed step-by-step:

Step 1: We have the equation 15x=12 \frac{1}{5}x = 12 .

Step 2: To isolate x x , multiply both sides of the equation by 5:

5×15x=5×12 5 \times \frac{1}{5}x = 5 \times 12

Step 3: Simplify both sides:

  • The left side simplifies to x x because 5×15=1 5 \times \frac{1}{5} = 1 , so x x is left alone.
  • The right side becomes 60 60 , since 5×12=60 5 \times 12 = 60 .

Therefore, the value of x x is 60 60 .

Therefore, the solution to the problem is x=60 x = 60 .

Answer

60 60

Exercise #10

Solve the equation

8x10=80 8x\cdot10=80

Video Solution

Step-by-Step Solution

To solve this linear equation, we need to isolate the variable x x . Here are the steps to follow:

  • Step 1: Simplify the equation by dividing both sides by 10. This gives us:

8x1010=8010 \frac{8x \cdot 10}{10} = \frac{80}{10}

This simplifies to:

8x=8 8x = 8

  • Step 2: Now, isolate x x by dividing both sides by 8:

8x8=88 \frac{8x}{8} = \frac{8}{8}

This simplifies to:

x=1 x = 1

Therefore, the solution to the equation 8x10=80 8x \cdot 10 = 80 is

x=1 x = 1 .

Answer

x=1 x=1

Exercise #11

Solve the equation

5x15=30 5x-15=30

Video Solution

Step-by-Step Solution

We start by moving the sections:

5X-15 = 30
5X = 30+15

5X = 45

Now we divide by 5

X = 9

Answer

x=9 x=9

Exercise #12

Solve the equation

20:4x=5 20:4x=5

Video Solution

Step-by-Step Solution

To solve the exercise, we first rewrite the entire division as a fraction:

204x=5 \frac{20}{4x}=5

Actually, we didn't have to do this step, but it's more convenient for the rest of the process.

To get rid of the fraction, we multiply both sides of the equation by the denominator, 4X.

20=5*4X

20=20X

Now we can reduce both sides of the equation by 20 and we will arrive at the result of:

X=1

Answer

x=1 x=1

Exercise #13

4x:30=2 4x:30=2

Video Solution

Step-by-Step Solution

To solve the given equation 4x:30=2 4x:30 = 2 , we will follow these steps:

  • Step 1: Recognize that 4x:304x:30 implies 4x30=2\dfrac{4x}{30} = 2.

  • Step 2: Eliminate the fraction by multiplying both sides of the equation by 30.

  • Step 3: Simplify the equation to solve for xx.

Now, let's work through each step:

Step 1: The equation is written as 4x30=2\dfrac{4x}{30} = 2.

Step 2: Multiply both sides of the equation by 30 to eliminate the fraction:
30×4x30=2×30 30 \times \dfrac{4x}{30} = 2 \times 30

This simplifies to:
4x=60 4x = 60

Step 3: Solve for xx by dividing both sides by 4:
x=604=15 x = \dfrac{60}{4} = 15

Therefore, the solution to the problem is x=15 x = 15 .

Checking choices, the correct answer is:

x=15 x = 15

Answer

x=15 x=15

Exercise #14

Solve for x x :

5x3=45 5x \cdot 3 = 45

Video Solution

Step-by-Step Solution

To solve the equation5x3=45 5x \cdot 3 = 45 , follow these steps:

1. First, identify the operation needed to solve forx x . In this case, we have a multiplication equation.

2. Therefore, we divide both sides of the equation by 15 (since 5×3=15 5 \times 3 = 15 ) to isolate x x :

x=4515 x = \frac{45}{15}

3. Calculate x x :

x=3 x = 3

Answer

x=3 x=3

Exercise #15

Solve the equation

7x+5.5=19.5 7x+5.5=19.5

Video Solution

Step-by-Step Solution

To solve the given equation 7x+5.5=19.5 7x + 5.5 = 19.5 , we'll follow these steps:

  • Step 1: Eliminate the constant term from the left side by subtracting 5.5 from both sides of the equation.
  • Step 2: Simplify the equation after subtraction to isolate the term with x x .
  • Step 3: Use division to solve for x x .

Now, let's work through each step:

Step 1: Subtract 5.5 from both sides.

We have:
7x+5.55.5=19.55.5 7x + 5.5 - 5.5 = 19.5 - 5.5

This simplifies to:
7x=14 7x = 14

Step 2: Divide both sides by 7 to solve for x x .

So, we divide by 7:
7x7=147 \frac{7x}{7} = \frac{14}{7}

This simplifies to:
x=2 x = 2

Therefore, the solution to the problem is x=2 x = 2 .

Answer

x=2 x=2

Exercise #16

Solve the equation:

6x2=24 6x \cdot 2 = 24

Video Solution

Step-by-Step Solution

To solve the equation 6x2=24 6x \cdot 2 = 24 , follow these steps:

1. First, identify the operation involved. In this case, it is multiplication.

2. Divide both sides of the equation by 12 (since 6×2=12 6 \times 2 = 12 ) to isolate x x :

x=2412 x = \frac{24}{12}

3. Calculate x x :

x=2 x = 2

Answer

x=2 x=2

Exercise #17

Solve for X:

28x3=7 \frac{2}{8}x-3=7

Video Solution

Step-by-Step Solution

To solve the equation 28x3=7 \frac{2}{8}x - 3 = 7 , we'll follow these steps:

  • Step 1: Simplify the fraction. The coefficient 28 \frac{2}{8} simplifies to 14 \frac{1}{4} .
  • Step 2: Eliminate the constant term by adding 3 to both sides of the equation.
  • Step 3: Solve for x x by removing the coefficient of x x using division.

Let's solve the equation step-by-step:

Step 1: Simplify the equation:
The equation 28x3=7 \frac{2}{8}x - 3 = 7 simplifies to 14x3=7 \frac{1}{4}x - 3 = 7 .

Step 2: Eliminate the constant term:
Add 3 to both sides to isolate the term involving x x :

14x3+3=7+3\frac{1}{4}x - 3 + 3 = 7 + 3

This simplifies to:

14x=10\frac{1}{4}x = 10

Step 3: Solve for x x :
Multiply both sides by the reciprocal of 14 \frac{1}{4} to solve for x x :

414x=4104 \cdot \frac{1}{4}x = 4 \cdot 10

This simplifies to:

x=40x = 40

Therefore, the solution to the equation is x=40 x = 40 .

Answer

40

Exercise #18

Solve for X:

15x4=6 \frac{1}{5}x-4=6

Video Solution

Step-by-Step Solution

To solve the equation 15x4=6\frac{1}{5}x - 4 = 6, we will follow these steps:

  • Step 1: Add 4 to both sides of the equation to eliminate the subtraction and isolate the fractional term.
  • Step 2: Multiply both sides by 5 to clear the fraction and solve for x x .

Let's apply these steps to solve the equation:

Step 1: Add 4 to both sides:
15x4+4=6+4 \frac{1}{5}x - 4 + 4 = 6 + 4
This simplifies to:
15x=10 \frac{1}{5}x = 10

Step 2: Multiply both sides by 5 to solve for x x :
5×15x=10×5 5 \times \frac{1}{5}x = 10 \times 5
This simplifies to:
x=50 x = 50

Therefore, the solution to the equation is x=50 x = 50 .

Answer

50

Exercise #19

Find the value of the parameter X

x+38x=4+3x x+3-8x=4+3-x

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow the procedure of simplifying and solving for x x :

  • Step 1: Simplify both sides of the equation.
  • Step 2: Combine like terms and move them to opposite sides to isolate x x .
  • Step 3: Solve for x x by performing necessary arithmetic operations.

Now, let's work through each step:

Step 1: Simplify both sides of the equation.
The given equation is x+38x=4+3x x + 3 - 8x = 4 + 3 - x .
Combine like terms on each side:
Left side: x8x+3=7x+3 x - 8x + 3 = -7x + 3
Right side: 4x+3=7x 4 - x + 3 = 7 - x
So the equation becomes: 7x+3=7x -7x + 3 = 7 - x .

Step 2: Get all terms involving x x on one side of the equation.
Add x x to both sides to combine the x x terms:
7x+x+3=7x+x -7x + x + 3 = 7 - x + x
Simplifies to: 6x+3=7 -6x + 3 = 7

Step 3: Solve for x x .
Subtract 3 from both sides to isolate terms involving x x : 6x+33=73 -6x + 3 - 3 = 7 - 3 6x=4 -6x = 4
Now, divide both sides by 6-6 to solve for x x : x=46=23 x = \frac{4}{-6} = -\frac{2}{3}

Therefore, the solution to the problem is x=23 x = -\frac{2}{3} .

Answer

23 -\frac{2}{3}

Exercise #20

Solve for X:

5x+203x=40+26x -5x+20-3x=40+2-6x

Video Solution

Step-by-Step Solution

To solve for x x , let's follow these steps:

  • Step 1: Combine like terms on both sides of the equation.
  • Step 2: Isolate the x x terms on one side.
  • Step 3: Solve for x x .

Let's begin with the left side of the equation:
5x+203x -5x + 20 - 3x simplifies to 8x+20 -8x + 20 .

Next, the right side of the equation:
40+26x 40 + 2 - 6x simplifies to 426x 42 - 6x .

The equation now is:
8x+20=426x -8x + 20 = 42 - 6x .

Step 2: Move all terms containing x x to one side and constant terms to the other:

First, add 8x 8x to both sides to move the x x terms together:
8x+8x+20=42+2x -8x + 8x + 20 = 42 + 2x
which simplifies to 20=42+2x 20 = 42 + 2x .

Next, subtract 42 42 from both sides to get:
2042=2x 20 - 42 = 2x
which simplifies to 22=2x -22 = 2x .

Step 3: Solve for x x by dividing both sides by 2:
x=222=11 x = \frac{-22}{2} = -11 .

Therefore, the solution to the problem is x=11 x = -11 .

Answer

11 -11