Which is the best way to fix the following run on sentence

Which matrix can be multiplied to the left of a vector matrix to get a new vector matrix ?

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

Iwill give ! if m∠a=59 and m∠3=81°, what is m∠b? m∠b= _[blank]_°