y(y-1)-x(x-1)因式分解
问题描述：
y(y-1)-x(x-1)因式分解
答
=y²-y-x²+x
=y²-x² -y+x
=(y-x)(y+x)-(y-x)
=(y-x)(y+x-1)
答
原式=y²-y-x²+x
=(y²-x²)-y+x
=(y+x)(y-x)-(y-x)
=(y-x)(y+x-1)