Hello, I have a test tomorrow and 150 math problems due tomorrow morning.

I had 4 people explain this to me in 4 different ways, but I always get stuck when I work on problems by myself.

Can someone please explain to me step by step how to factor:

3x^{3}+4xy+y^{2 }6x^{2}-7xy-5y^{2 }15x^{2}-31xy+10y^{2}

^{ Thank you }