Combine like terms.

8 + 16r - 9r

A.

8 + 7r

B.

15r

C.

15

D.

8 - 7r

First, you subtract 16r by 9r, which gives you 7r, so that leaves you with 8 + 7r. You cannot add a normal number and a number with a variable, so that's all you can do, so your answer is A.