Question

Factor completely
5r^4-3125

Answer 1

Factor out what's common to both first:

5(r^4-625)
5(r^2-25)(r^2+25)
5(r+5)(r-5)(r^2+25)

Answer 2

this a hard one

Answer 3

I don't really consider three steps hard

Answer 4

This is just common factoring and difference of squares. It's easier than what we did because not that many steps are involved