Practice!

Sample Problem

In the following sequence of steps, which property is used to move from step 3 to step 4?

9 + (4 – 9) = 4:

1. 9 + (4 – 9) = 9 + [4 + (-9) ]

2. = 9 + [ (-9) + 4]

3. = [9 + (-9) ] + 4

4. = 0 + 4

5. = 4

Solution

The inverse property of addition is used because a positive number cancels out with its negative to equal 0.