When solving the equation 4 (3x2 + 2) - 9 = 8x2 + 7, Emily
wrote 4 (3x + 2) = 8x2 + 16 as her first step. Which
property justifies Emily's first step?
A addition property of equality
B commutative property of addition
multiplication property of equality
distributive property of multiplication over addition
A
In this example, Emily is adding 9 to both sides of the equation. Doing so keeps the equation equal since the operation was done to both sides, so this must be the addition property of equality.
