Which property is the reason for number 3? 1. ∠abc ≅ ∠def given 2. ∠hgi + ∠abc = 180° given 3. ∠hgi + ∠def = 180° select one: a. subtraction property of equality b. reflexive property of equality c. substitution property of equality d. segment addition postulate

It is solution c. You substitute ABC for DEF.

The given equation is:

0 + 7y + 2 = 7y + 2

This equation is showing that addition of 0 leaves the expression unchanged. 0 is known as the Additive Identity this means if we add or subtract 0 from any expression, number or equation the result won't be changed.

Therefore, the equation satisfied the property of Additive Identity of Real Numbers.