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

Exercise #1

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 #2

Solve for X:

4x7=x+5 4x - 7 = x + 5

Video Solution

Step-by-Step Solution

To solve forx x , first, get all terms involving x x on one side and constants on the other. Start from:

4x7=x+5 4x - 7 = x + 5

Subtract x x from both sides to simplify:

3x7=5 3x - 7 = 5

Add 7 to both sides to isolate the terms withx x :

3x=12 3x = 12

Divide each side by 3 to solve forx x :

x=4 x = 4

Thus, x x is 4 4 .

Answer

4 4

Exercise #3

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 #4

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 #5

Solve for X:

7x3=4x+9 7x - 3 = 4x + 9

Video Solution

Step-by-Step Solution

To solve the equation 7x3=4x+9 7x - 3 = 4x + 9 , follow these steps:

1. Subtract 4x 4x from both sides to get:

7x4x3=9 7x - 4x - 3 = 9

2. Simplify the equation:

3x3=9 3x - 3 = 9

3. Add 3 3 to both sides:

3x=12 3x = 12

4. Divide both sides by 3 3 :

x=4 x=4

Answer

4

Exercise #6

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 #7

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 #8

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 #9

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 #10

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 #11

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 #12

Solve for X:

3x+6=12 3x + 6 = 12

Video Solution

Step-by-Step Solution

Step-by-step solution:

1. Start with the equation: 3x+6=12 3x + 6 = 12

2. Subtract 6 from both sides: 3x+66=126 3x + 6 - 6 = 12 - 6 , which simplifies to 3x=6 3x = 6

3. Divide both sides by 3 to solve for x: x=63 x = \frac{6}{3}

4. Simplify the division: x=2 x = 2

Answer

2

Exercise #13

Solve for X:

5x+10=3x+18 5x + 10 = 3x + 18

Video Solution

Step-by-Step Solution

To solve the equation 5x+10=3x+18 5x + 10 = 3x + 18 , follow these steps:

1. Subtract 3x 3x from both sides to get:

5x3x+10=18 5x - 3x + 10 = 18

2. Simplify the equation:

2x+10=18 2x + 10 = 18

3. Subtract 10 10 from both sides:

2x=8 2x = 8

4. Divide both sides by 2 2 :

x=4 x = 4

Answer

4

Exercise #14

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 #15

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 #16

5x+7=32 5x+7=32

Video Solution

Step-by-Step Solution

To solve this linear equation, follow these steps:

  • Step 1: Isolate the term with x x by subtracting 7 from both sides of the equation.
  • Step 2: Perform the subtraction to simplify the equation.
  • Step 3: Divide both sides by 5 to solve for x x .

Let’s perform each step:

Step 1: Subtract 7 from both sides:
5x+77=327 5x + 7 - 7 = 32 - 7

This simplifies to:
5x=25 5x = 25

Step 2: Divide both sides by 5 to isolate x x :
x=255 x = \frac{25}{5}

Perform the division:
x=5 x = 5

Hence, the solution to the equation 5x+7=32 5x + 7 = 32 is x=5 x = 5 .

Answer

x=5 x=5

Exercise #17

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 #18

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 #19

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 #20

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