Pleasee help, its about systems with 3 variables

Last year amusement park received 236,758 visitors it was open every day of the year but 7 holliday’s what was the average number of visitors to the park per day

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? a. identity property of addition b. inverse property of addition c. associative property of addition d. commutative property of addition

The solution set for 5v2 – 125 = 0 is