So one problem is f(x)=x^3 , In my head I know its x^(1/3) because

y=x^3

Then i think I Do the third square root to both sides to get that answer but am not sure.

This is the one where Im haveing the most trouble

f(x)=(3x+1)/(2x-5) So I Multipy each side by 2x-5 and get

y(2x-5) which factors into

2xy-5y=3x+1 and am not sure what to do from here

Any help would be greatly appreciated.

The answer in the back of the book is y=(5x+1)/(2x-3)

even with that I cant figure out how they came up with it