Examples with solutions for Solving an Equation by Multiplication/ Division: Equations with variables on both sides

Exercise #1

Solve for X:

3x=18 3x=18

Video Solution

Step-by-Step Solution

We use the formula:

ax=b a\cdot x=b

x=ba x=\frac{b}{a}

Note that the coefficient of X is 3.

Therefore, we will divide both sides by 3:

3x3=183 \frac{3x}{3}=\frac{18}{3}

Then divide accordingly:

x=6 x=6

Answer

6 6

Exercise #2

Solve for X:

x4=3 \frac{x}{4}=3

Video Solution

Step-by-Step Solution

We use the formula:

ax=b a\cdot x=b

x=ba x=\frac{b}{a}

We multiply the numerator by X and write the exercise as follows:

x4=3 \frac{x}{4}=3

We multiply by 4 to get rid of the fraction's denominator:

4×x4=3×4 4\times\frac{x}{4}=3\times4

Then, we remove the common factor from the left side and perform the multiplication on right side to obtain:

x=12 x=12

Answer

12 12

Exercise #3

Solve for X:

5x=38 5x=\frac{3}{8}

Video Solution

Step-by-Step Solution

ax=cb ax=\frac{c}{b}

x=cba x=\frac{c}{b\cdot a}

Answer

340 \frac{3}{40}

Exercise #4

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 #5

Solve for X:

18x=34 \frac{1}{8}x=\frac{3}{4}

Video Solution

Step-by-Step Solution

We use the formula:

abx=cd \frac{a}{b}x=\frac{c}{d}

x=bcad x=\frac{bc}{ad}

We multiply the numerator by X and write the exercise as follows:

x8=34 \frac{x}{8}=\frac{3}{4}

We multiply both sides by 8 to eliminate the fraction's denominator:

8×x8=34×8 8\times\frac{x}{8}=\frac{3}{4}\times8

On the left side, it seems that the 8 is reduced and the right section is multiplied:

x=244=6 x=\frac{24}{4}=6

Answer

6 6

Exercise #6

Solve for X:

5x=3 5x=3

Video Solution

Answer

35 \frac{3}{5}

Exercise #7

Solve for X:

6x=3 6x=3

Video Solution

Answer

12 \frac{1}{2}

Exercise #8

Solve for X:

8x=5 8x=5

Video Solution

Answer

58 \frac{5}{8}

Exercise #9

Solve for X:

7x=4 7x=4

Video Solution

Answer

47 \frac{4}{7}

Exercise #10

Solve for X:

4x=18 4x=\frac{1}{8}

Video Solution

Answer

132 \frac{1}{32}

Exercise #11

7y=27 -7y=-27

Video Solution

Answer

367 3\frac{6}{7}

Exercise #12

6x=18 -6x=18

Video Solution

Answer

3 -3

Exercise #13

Solve for X:

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

Video Solution

Answer

2 2

Exercise #14

Solve for X:

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

Video Solution

Answer

1 -1

Exercise #15

8x+4=4 8x+4=4

Video Solution

Answer

x=0 x=0

Exercise #16

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

Video Solution

Answer

x=5 x=5

Exercise #17

14x6=134 14x-6=134

Video Solution

Answer

x=10 x=10

Exercise #18

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

Video Solution

Answer

x=1 x=-1

Exercise #19

Find the value of the parameter X

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

Video Solution

Answer

14 -\frac{1}{4}

Exercise #20

Solve for X:

10x=611 10x=\frac{6}{11}

Video Solution

Answer

355 \frac{3}{55}