For this case we have the following polynomials:
5x ^ 5 + 2x - 1
6x ^ 5 + x + 8
Adding we have:
(5x ^ 5 + 2x - 1) + (6x ^ 5 + x + 8)
We group in similar terms:
x ^ 5 (5 + 6) + x (2 + 1) + (-1 + 8)
Rewriting we have:
11x ^ 5 + 3x + 7
Answer:
11x ^ 5 + 3x + 7
option D