When x is decreased by 129 and then that number is multiplied by 129, the result is 129. What is the value of x?

Simonne used the following steps to simplify the given expression. 12-3(-2x+4) step 1: 12+(-)+(-3)(4) step 2: 12+6x+(-12) step 3: 12+(-12)+6x step 4: 0+6x step 5: 6x what property of real numbers was used to transition from step 3 to step 4? •identity property of addition •inverse property of addition •associative property of addition •commutative property of addition