x^2-4y^2-4y-1

问题描述:

x^2-4y^2-4y-1
因式分解

x²-4y²-4y-1
=x²-(4y²+4y+1)
=x²-(2y+1)²
=[x+(2y+1)][x-(2y+1)]
=(x+2y+1)(x-2y-1)