Well I've got a bit of a monster series of exponential problems. I'm not gonna ask the answer necessarily, but I'd like to have some help in double checking my own answers. they'll all be attached

Question

anonymous · Answer

$$(-11a ^{7}x ^{3}y ^{-2})^{-1} (2xy ^{3}) $$
Simplify . 
My answer was -11c^4

zepdrix · Answer

What? I don't see a $\Large\rm c$ in the problem anywhere...

anonymous · Answer

CRABS. I MADE A MISTAKE

anonymous · Answer

2. -11c^4
3. Frankly i'm lost there
4. and here... 
5. 10y^-8
6. y^35
7. 625x^16
9. (a^8)(b^9)
11.1/(8(a^3)b)
12. 1/a
13. ((a^5)(b^2))/2
14. ohmygod