因式分解x方-y方+4y-4x
问题描述：
因式分解x方-y方+4y-4x
答
=(x+y)(x-y)+4(y-x)
=(x-y)(x+y-4)
答
(X+Y)(X-Y)-4(X-Y)=(X+Y-4)(X-Y)
答
x^2-y^2+4y-4x
=(x+y)(x-y)-4(x-y)
=(x+y-4)(x-y)