若将x-y看成一个整体,则化简(x-y)^2—3(x-y)-4(x-y)^2+5(x-y)

问题描述:

若将x-y看成一个整体,则化简(x-y)^2—3(x-y)-4(x-y)^2+5(x-y)

原式=-3(x-y)²+2(x-y)
=(x-y)(-3x+y+x-y) (提公因式法)
=-2x(x-y)x