Question

9. What property was used to get from line 1 to line 2?

line 1: 16 + 3x + 5 + 2x
line 2:2x + 3x + 5 + 16
line 3:5x + 21

Answer 1

Answer: Commutative Property of Addition

This property says that A+B = B+A. The order of addition doesn't matter.

As an example, 2+3 = 3+2 since both sides evaluate to 5.