Bitcoin question... to some degree

Can I use the gpu of an amd a10-6800k to mine bitcoins whilst running a second gpu (a radeon HD 7870) for games, schoolwork and whatnot?

Simple answer: Yes you can

 

Similar if you have an Intel CPU, it has Onboard graphics like HD 3000 or 4000, you can use it to mine bitcoins, but the hashrate is really bad.

thanks. Any details on how to?