Question

-3x+6=21
A) x=-9
B) x=9
C) x=-5
D) x=5
E) x=4

Answer 1

Answer: x = -5

Work Shown

-3x+6 = 21

-3x = 21-6

-3x = 15

x = 15/(-3)

x = -5

Let's check that answer. Replace every copy of x with -5.

-3x+6 = 21

-3(-5)+6 = 21

15+6 = 21

21 = 21

We have confirmed the answer is correct.