解:x-2(x+2y)+3(y-2x) =x-2x-4y+3y-6x =﹣7x-y ∵ x=-2,y=1 ∴原式=﹣7×(﹣2)-1 =13
x-2(x+2y)+3(y-2x)=x-2x-4y+3y-6x=-7x-y=14-1=13
x-2(x+2y)+3(y-2x)=-y-7x=-1+14=13
x-2x-4y+3y-6x=-y-7x=13