分解因式：x²-y²-2y-1 ?
问题描述：
分解因式：x²-y²-2y-1 ?
答
x²-y²-2y-1
=x²-(y+1)²
=(x+y+1)(x-y-1)
分解因式：x²-y²-2y-1 ?
x²-y²-2y-1
=x²-(y+1)²
=(x+y+1)(x-y-1)