What’s the answer I’m struggling?

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 coordinates of a, b, and c in the diagram are a(p,4), b(6,1), and c(9,q). which equation correctly relates p and q? hint: since is perpendicular to , the slope of × the slope of = -1. a. p - q = 7 b. q - p = 7 c. -q - p = 7 d. p + q = 7

How do you use the elimination method for this question? explain, because i really want to understand!