Question

factor 48y^4-3y^2

Answer 1

3y^2(16y^2-1)

Answer 2

do you see what I did?

Answer 3

First take out common factors:
3y^2(16y^2-1)
Then rewrite the contents of the parentheses as difference of two squares, apply
(a^2-b^2)=(a+b)(a-b)
to complete the factorization.

Answer 4

so next step is rewrite 3y^2(16y^2 -1) = 3y^2((4y)^2-1^2) now what?

Answer 5

Try set a=4y, b=1 and use the above identity.