Simonne used the following steps to simplify the given expression.


12 - 3(-2x + 4)


Step 1: 12 + (–3)·(–2x) + (–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?