Complete the following stepped out solution to that -8+c+8-d is equivalent to c-d

-8+?+c-d Commutative Property of Addition
?+c-d Inverse Property of Addition
c-d Identity Property of Addition

The missing steps in the solution are:

-8+c+8-d is equivalent to (-8+8) + (c-d) Associative Property of Addition
-8+c+8-d is equivalent to 0 + (c-d) Simplification (since -8+8 equals 0)
-8+c+8-d is equivalent to c-d Identity Property of Addition (since 0 plus any number equals that number)

?+c-d

Inverse Property of Addition

The missing step is:

?+c-d is equivalent to c-d Inverse Property of Addition (since ?+c equals c)