Question

19. Solve the equation 3(x - 7) = 42.
• A. 21
B. 49
C. 36
D.7

Answer 1

The correct answer is option A. 21

Explanation:

It is given an expression in variable x, 3(x - 7) = 42

To find the value of x

Let 3(x - 7) = 42

3x - (3 * 7) = 42 (Open the bracket)

3x - 21 = 42

3x = 42 + 21

3x = 63

x = 63/3 = 21

Therefore the value of x = 21

The correct answer is option A. 21

Answer 2

For this case we must solve the following equation:

`3 (x-7) = 42`

Applying distributive property to the terms within the parenthesis we have:

`3x-21 = 42`

Adding 21 to both sides of the equation:

`3x = 42 + 21\\3x = 63`

Dividing between 3 on both sides of the equation:

`x = \frac {63} {3}\\x = 21`

Answer:

`x = 21`