First of all, we need to put the variables apart and the numbers apart. So we add 7x on both sides: -7x + 7x + 15 = -7x + 7x + 12 0x + 15 = 0x + 12 15 = 12
This answer is impossible since 15 can never be equal to 12. So there are no values of x that can make the equation true.