(3r2+7r+1)+(4r2-8r-2)

A. 8r2+15r-1

B. 7r2-r-1

C. 7r2-15r-3

D. -r2-r-1

Solution:

Simply add the like terms together:

(3r2+7r+1)+(4r2-8r-2) = 7r2-r-1

Therefore, the answer is B. 7r2-r-1.