1.（（y+2x)(-2x+y)+4(x+2y)^2)/3y =(y^2-4x^2+4x^2+16xy+16y^2)/3y=(17y^2+16xy)/3y=17y/3+16x/32.（2(x-y)^3-8(x-y）^2(x+y)+6y(x-y)^2）/2（x-y)^2=[(x-y)^2(2x-2y-8x-8y+6y)/2(x-y)^2=(-6x-4y)/2=-3x-2y