First: Do us (and yourself!) a favour and use brackets! Otherwise your equations are not understandable.

Example: f(x)=5^x-2-15 and g(x)=10 should read f(x)=5^(x-2)-15 and g(x)=10

Second: I'll do #11 and leave the rest for you. If you need some further assistance show your work so we know where we could help you.