Answer:
x = -4
Explanation:
12x+7=5x-21
12x+7-5x=5x-21-5x [Subtract 5x from both sides]
7x + 7 = -21 [Combine like terms]
7x + 7 - 7= -21 - 7 [Subtract 7 from both sides]
7x = -28 [Combine like terms]
7x/7 = -28/7 [Divide both sides by 7]
x = -4 [Simplify]
CHECK:
Does 12x+7=5x-21 when x = -4?
12*(-4)+7=5*(-4)-21 ?
= 48 + 7 = -20 - 21 ?
- 41 = - 42 YES