因式分解：9（x-y）²-12（x-y）+4=
问题描述：
因式分解：9（x-y）²-12（x-y）+4=
答
9(x-y)^2-12(x-y)+4=[3(x-y)]^2-2*3*2(x-y)+2^2=[3(x-y)-2]^2=(3x-3y-2)^2
因式分解：9（x-y）²-12（x-y）+4=
9(x-y)^2-12(x-y)+4=[3(x-y)]^2-2*3*2(x-y)+2^2=[3(x-y)-2]^2=(3x-3y-2)^2