Answer:
x = -9
Step-by-step explanation:
6x + 6 = 3x – 21
Subtract 3x from each side
6x-3x + 6 = 3x-3x – 21
3x+6 = -21
Subtract 6 from each side
3x+6-6 = -21-6
3x = -27
Divide by 3
3x/3 = -27/3