Im gonna stat by rearranging the equations to put like terms next to each other. After that the only thing you have to do is combine the like terms together.
(A)
10x + 7x + 7 - 7
The sevens cancel out leaving:
10x + 7x
Add the terms:
ANSWER: 17x
(B)
-10b^2 - 8b^2 + 8b + 3b + 6 - 6
Sixes cancel out
-10b^2 - 8b^2 + 8b + 3b
Combine like terms
ANSWER: -18b^2 + 11b