Answer:
8.9r + (5s + 10)
actually the parenthesis aren't necessary...
8.9r + 5s + 10
Explanation:
You can change a subtraction to addition if you change the second term to the opposite sign. This problem is like advanced mode of "Add the Opposite"
8.9r - (-5s - 10)
= 8.9r + (+5s + 10)
= 8.9r + (5s + 10)
= 8.9r + 5s + 10