Examples with solutions for Solving an Equation by Multiplication/ Division: Rearranging Equations

Exercise #1

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 #2

5x+6=56 5x+6=56

How much is X X worth?

Video Solution

Step-by-Step Solution

To solve the equation 5x+6=56 5x + 6 = 56 , we will follow these steps:

  • Step 1: Subtract 6 from both sides of the equation to eliminate the constant term on the left-hand side.
  • Step 2: Simplify the resulting equation.
  • Step 3: Divide both sides by 5 to isolate x x .

Now, perform each step:

Step 1: Subtract 6 from both sides:
5x+66=566 5x + 6 - 6 = 56 - 6

Step 2: Simplify both sides:
5x=50 5x = 50

Step 3: Divide both sides by 5 to solve for x x :
x=505 x = \frac{50}{5}

Step 4: Simplify the division:

x=10 x = 10

Therefore, the solution to the problem is x=10 x = 10 .

Answer

10 10

Exercise #3

10+9x=91 10+9x=91

How much is X worth?

Video Solution

Step-by-Step Solution

To solve the equation 10+9x=91 10 + 9x = 91 , we'll follow these steps:

  • Step 1: Eliminate the constant term on the left side by subtracting 10 from both sides of the equation.

10+9x10=9110 10 + 9x - 10 = 91 - 10 9x=81 9x = 81

  • Step 2: Solve for x x by dividing each side of the equation by the coefficient of x x , which is 9.

9x9=819 \frac{9x}{9} = \frac{81}{9} x=9 x = 9

Hence, the value of x x is 9 9 .

Answer

9 9

Exercise #4

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 #5

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 #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:

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 #8

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 #9

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 #10

Solve for X:

x+5=11x x+5=11x

Video Solution

Step-by-Step Solution

Let's solve the equation x+5=11x x + 5 = 11x step-by-step.

  • Step 1: Isolate the variable x x
    Start by getting all terms involving x x on one side of the equation. We can do this by subtracting x x from both sides:
    x+5x=11xx x + 5 - x = 11x - x
  • This simplifies to:
    5=10x 5 = 10x
  • Step 2: Solve for x x
    Now, divide both sides of the equation by 10 to solve for x x :
    510=10x10 \frac{5}{10} = \frac{10x}{10}
  • This further simplifies to:
    x=12 x = \frac{1}{2}

Therefore, the solution to the equation x+5=11x x + 5 = 11x is x=12 x = \frac{1}{2} .

Answer

12 \frac{1}{2}

Exercise #11

Solve for X:

5x+4=7x 5x+4=7x

Video Solution

Step-by-Step Solution

To solve the equation 5x+4=7x 5x + 4 = 7x , we will proceed as follows:

  • Step 1: Subtract 5x 5x from both sides to simplify the equation.

The equation is:
5x+45x=7x5x 5x + 4 - 5x = 7x - 5x

This simplifies to:
4=2x 4 = 2x

  • Step 2: To solve for x x , divide both sides by 2 to isolate x x .

Perform the division:
42=2x2 \frac{4}{2} = \frac{2x}{2}

This gives us:
2=x 2 = x

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

Answer

2 2

Exercise #12

Solve for X:

3x+8=7x12 -3x+8=7x-12

Video Solution

Step-by-Step Solution

We will solve the equation step by step:

Given equation:
3x+8=7x12 -3x + 8 = 7x - 12

  • Step 1: Move all x x -terms to one side by adding 3x 3x to both sides.
    3x+3x+8=7x+3x12 -3x + 3x + 8 = 7x + 3x - 12
    This simplifies to:
    8=10x12 8 = 10x - 12
  • Step 2: Move constant terms to the opposite side by adding 12 12 to both sides.
    8+12=10x12+12 8 + 12 = 10x - 12 + 12
    Which simplifies to:
    20=10x 20 = 10x
  • Step 3: Solve for x x by dividing both sides by 10 10 .
    2010=10x10 \frac{20}{10} = \frac{10x}{10}
    This gives us:
    x=2 x = 2

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

Answer

2 2

Exercise #13

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 #14

2b3b+4=5 2b-3b+4=5

b=? b=\text{?}

Video Solution

Step-by-Step Solution

Let's first arrange the equation so that on the left-hand side we have the terms with the coefficient b b and on the right-hand side the numbers without the coefficient b b .

Remember that when we move terms across the equals sign, the plus and minus signs will change accordingly:

2b3b=54 2b-3b=5-4

Let's now solve the subtraction exercise on both sides:

1b=1 -1b=1

Finally, we can divide both sides by -1 to find our answer:

b=1 b=-1

Answer

-1

Exercise #15

20+20x3x=88 20+20x-3x=88

x=? x=\text{?}

Video Solution

Step-by-Step Solution

To solve this problem, we need to find x x in the equation:

20+20x3x=88 20 + 20x - 3x = 88

Step 1: Combine like terms on the left-hand side of the equation. The terms involving x x are 20x 20x and 3x-3x.

20x3x=17x 20x - 3x = 17x

Thus, the equation becomes:

20+17x=88 20 + 17x = 88

Step 2: Isolate the x x -related terms by moving the constant term to the right-hand side. To do this, subtract 20 from both sides:

17x=8820 17x = 88 - 20

17x=68 17x = 68

Step 3: Solve for x x by dividing both sides of the equation by 17:

x=6817 x = \frac{68}{17}

x=4 x = 4

Therefore, the solution to the problem is x=4 x = 4 .

Answer

4 4

Exercise #16

2+3a+4=0 2+3a+4=0

a=? a=\text{?}

Video Solution

Step-by-Step Solution

To solve the equation 2+3a+4=0 2 + 3a + 4 = 0 , follow these steps:

  • Step 1: Combine the constant terms on the left side.
    The terms 2 2 and 4 4 can be combined to get 6 6 .
    Hence, the equation becomes 3a+6=0 3a + 6 = 0 .
  • Step 2: Isolate the term with the variable a a .
    Subtract 6 6 from both sides to get 3a=6 3a = -6 .
  • Step 3: Solve for a a by dividing both sides by the coefficient of a a , which is 3 3 .
    Thus, a=63=2 a = \frac{-6}{3} = -2 .

Therefore, the solution to the problem is a=2 a = -2 .

Answer

2 -2

Exercise #17

m+3m17m+6=20 m+3m-17m+6=-20

m=? m=\text{?}

Video Solution

Step-by-Step Solution

To solve the problem, we will use the following steps:

  • Step 1: Simplify the equation by combining like terms.
  • Step 2: Isolate the variable m m using algebraic methods.
  • Step 3: Solve for m m and verify the solution.

Let's begin:

Step 1: Simplify the equation m+3m17m+6=20 m + 3m - 17m + 6 = -20 .
Combine the coefficients of m m :

(1+317)m+6=20 (1 + 3 - 17)m + 6 = -20

This simplifies to:

13m+6=20 -13m + 6 = -20

Step 2: Isolate m m .
Subtract 6 from both sides:

13m+66=206 -13m + 6 - 6 = -20 - 6

Simplifies to:

13m=26 -13m = -26

Step 3: Solve for m m by dividing both sides by -13:

m=2613 m = \frac{-26}{-13}

The division simplifies to:

m=2 m = 2

Therefore, the solution to the problem is m=2 m = 2 , which corresponds to choice 2 in the given options.

Answer

2

Exercise #18

4a+524+a=2a 4a+5-24+a=-2a

a=? a=?

Video Solution

Step-by-Step Solution

To solve the equation 4a+524+a=2a 4a + 5 - 24 + a = -2a , follow these steps:

  • Step 1: Start by combining like terms on the left side of the equation:

4a+a+524=2a 4a + a + 5 - 24 = -2a

This simplifies to:

5a19=2a 5a - 19 = -2a

  • Step 2: Move all terms involving a a to one side of the equation and constant terms to the other side:

Add 2a 2a to both sides to collect all terms with a a :

5a+2a=19 5a + 2a = 19

This simplifies to:

7a=19 7a = 19

  • Step 3: Solve for a a by dividing both sides by 7:

a=197 a = \frac{19}{7}

Thus, the value of a a is 197 \frac{19}{7} , which can be written as a mixed number:

a=257 a = 2\frac{5}{7} .

Upon verifying with the given choices, the correct answer is choice 1: 257 2\frac{5}{7} .

Answer

257 2\frac{5}{7}

Exercise #19

8002xx=803 800-2x-x=803

Video Solution

Step-by-Step Solution

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

  • Step 1: Combine like terms on the left side of the equation.
  • Step 2: Isolate the variable x x on one side of the equation.
  • Step 3: Solve for x x and simplify the result.

Now, let's work through each step:
Step 1: The left side of the equation is 8002xx 800 - 2x - x . Combine the terms with x x :
This becomes 8003x=803 800 - 3x = 803 .

Step 2: Subtract 800 from both sides to isolate the term with x x :
8003x800=803800 800 - 3x - 800 = 803 - 800
This simplifies to 3x=3 -3x = 3 .

Step 3: Divide both sides by -3 to solve for x x :
x=33 x = \frac{3}{-3}
Thus, x=1 x = -1 .

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

Answer

x=1 x=-1

Exercise #20

14x6=134 14x-6=134

Video Solution

Step-by-Step Solution

To solve the equation 14x6=134 14x - 6 = 134 , follow these steps:

  • Step 1: Isolate the term involving x x . We do this by adding 6 to both sides of the equation to eliminate the constant term:

14x6+6=134+6 14x - 6 + 6 = 134 + 6

This simplifies to:

14x=140 14x = 140

  • Step 2: Solve for x x by dividing both sides by 14 (the coefficient of x x ):

14x14=14014 \frac{14x}{14} = \frac{140}{14}

This gives us:

x=10 x = 10

Therefore, the solution to the problem is x=10 x = 10 .

Answer

x=10 x=10