Step-by-step explanation: Distribute the numbers: 4 times x is 4x, 4 times 3 is 12. Then you have the equation: -x+4x +12 = -12. Now, choose a random number, maybe -4. A negative plus a negative cancels out so you are left with 4-16(Because you distribute the number) +12 = -12. 4-16 is -12. -12 plus 12 equals 0.
