Simplify the following:
-9 b^9-11 n-(6 b^9-7 n)
-(6 b^9-7 n) = 7 n-6 b^9:
-9 b^9-11 n+7 n-6 b^9
Grouping like terms, -9 b^9-11 n-6 b^9+7 n = (7 n-11 n)+(-9 b^9-6 b^9):
(7 n-11 n)+(-9 b^9-6 b^9)
7 n-11 n = -4 n:
-4 n+(-9 b^9-6 b^9)
-9 b^9-6 b^9 = -15 b^9:
Answer: | -15b^9 - 4n
