Having some difficult with a few problems

if you could explain how to do the equation that would be great!

1)

the answer has to be in the form of f(x)/g(x)

2) After fully simplifying the expression

3)Simplify the complex rational expression

into a standard rational expression.

4)

solve for a and b

5)

use the rules

and

.

6)Evaluate the expression

using

.

I got 264 for this one...but we are allowed to check out work..and it says im wrong?

7)

If you rationalize the denominator of

then you will get

solve for r,x,n

Thanks for any help!