Question

1) (х^2+1)^2-4х^2=
2) 4у^2-(у-с)^2=

Answer 1

1) (х²+1)²-4х²=(х²+1-2х)(х²+1+2х)=(х²-2х+1)(х²+2х+1)=(х-1)²(х+1)².
2) 4у²-(у-с)²=(2у-(у-с))(2у+у-с)=(2у-у+с)(3у-с)=(у+с)(3у-с).