Need help. Test on Monday!

Hello everyone.

I am in desperate need of help. I am in college algebra and just can NOT get modeling down, and I have a test on Monday! I am completely lost, and realize I should have gotten help before now but now I have no choice but to learn it all today and tomorrow. It's just the set up, I know how to do the problems. Is there any where besides my text that I can get help with these application problems? They're killing me, and I'm really worried I'm gonna fail this first test.

I do have a direct question though. I've been working through these the best I can, and just can not solve this one no matter what I do.

A woman cycles 8 mi/h faster than she runs. Every morning she cycles 4 mi and runs 2.5 mi, for a total of one hour of exercise. How fast does she run?

I know that her running speed is x, and that her cycling speed is 8+x, but I still can't get anywhere. Please help if you can. :(