Please help me understand how to solve rational equations. I've always had trouble with solving these. I do problems thinking that I would get better but every time there is a new problem that just gets me stuck...

The problem statement, all variables and given/known data

1. Solve -

The problem statement, all variables and given/known data

2. Solve -

The problem statement, all variables and given/known data3. A man sold a car for 1000$ which is 25% more than what he had paid for the car. How much did the man pay for the car?

I also have a question where can I find a good book(s) that will contain problems, rational equations, percents, radicals, graphs, etc... and will in detail show you how to do each problem... Starting from the simplest to the hardest...I need to study for an exam and a lot of the material I have forgotten how to do.