I really need help I’m very confused

10: -11n^5

12: 6k^2 -6k+7

Step-by-step explanation:

Ok so what your gonna do is add or subtract the ones with the same exponent.

so -15+4= -11 since they are both n^5 you can add them so your answer is:

-11n^2

now you have 8k^2-k-5k+7-2k. so you are gonna rearrange them so the same exponents are together.(keep the sign in front in front, if no sign it is positive)

8k^2-2k^2-5k-k+7

add like exponents

6k^2-6k+7

unless if u could do my questions, if not i wouldn't want to