Answer: x = -11
Step-by-step explanation: First distribute or multiply through the parentheses on the left side of the equation.
When we do this, we get 3x + 15 = x - 7.
Then subtract x to get 2x + 15 = -7.
Then subtract 15 to get 2x = -22.
Then divide both sides of the equation by 2 and we find that x = -11.