Hello people! I need help with two math problems. They ask me to factor: 25a to the fourth - 14a squared b to the fourth + b to the eigth.

factor: 3a to the fourth + 48b to the fourth - 36a squared b squared.

I cannot figure out either one. With the first I need a number squared that equals 24, which is impossible of course, and the second I figured out I need a number squared that equals 20 which is also impossible (I figured that out with my own made-up equation.) Will someone show me how to solve these problems? I have tryed ever thing I can think of. Thank-you.