先化簡,再求值:[(x-y)2+(x-y)(x+y)]÷x,其中x=-1,y=12.

先化簡,再求值:[(x-y)2+(x-y)(x+y)]÷x,其中x=-1,y=12.

[(x-y)2+(x-y)(x+y)]÷x,=(x2-2xy+y2+x2-y2)÷x,=(2x2-2xy)÷x,=2x-2y,當x=-1,y=12,原式=2×(-1)-2×12=-3.