Question

What is 3x + 42 = 21 ?

Answer 1

To find 3x + 42 = 21, you have to subtract 42 from both sides of the equation.

3x + 42 - 42 = 21 - 42

3x = -21

Now, you have to divide 3 from both sides to get your desired answer.

$\frac{3x}{3}$ = $\frac{-21}{3}$

x = -7

The final answer is -7.

Answer 2

The answer would be -7. Explanation: You would do the opposite of addition so you would subtract 42 on both sides so on the right side it would get rid of the 42, then you would subtract it from the 21 so what's 21-42? The answer would be -21. Then you would divide 3 on each side so 3 divided by 3 would cancel that. So then you would do 3/-21 which would be -7. (: