I need help factoring polynomials. I have been pretty good going to my teacher after school this year, but she had a scholastic bowl meet and could not help me!

Tomorrow, I have a quiz on factoring polynomials. I have ALWAYS had trouble factoring throughout my life. I NEED help, please! I have gone over my notes, looked at the book, and it just doesn't get through! I have an A in the class and tomorrow is the last day of this semester! I NEED to get an A on this quiz if I want to keep my A. Please help!

For a problem such as this:

$\displaystyle 3a^2bx + 15cx^2y + 25ad^3y$ - needs to be factored.

I wrote it like this:

$\displaystyle 1*3*a*a*b*x+1*3*5*c*x*x+1*5*5*d*d*d*y$ to help me find the GCF.

The GCF would be...1? I can't take an variables out because the three terms don't have an a, b, x, or y each!

Also, I have other questions but we'll start with this one first...