Question

For which value of x is 3x + 5x = 8x a TRUE statement?

A) -5

B) 5

C) Both A and B

D) Neither A nor B

Answer 1

3x + 5x = 8x

8x = 8x

For any value of x, this equation will always be true.

Therefore the answer has to be C.

Answer 2

Substitute 5 and -5 into the equation and solve.


3x +5x = 8x

3(5) + 5(5) = 8(5)
15 + 25 = 40
40 = 40 (True)

3(-5) + 5(-5) = 8(-5)
-15 + (-25) = -40
-40 = -40 (True)

C is the correct answer.

Sorry the easiest way is

8x = 8x and plug in 5 and (-5). Its the same but takes away some addition.