x-2y=0x=2y(x-y)/(x+2y)÷(x^2-y^2)/(x^2+4xy+4y^2)-2=(x-y)/(x+2y)*(x+2y)^2/(x+y)(x-y)-2=(x+2y)/(x+y)-2=(2y+2y)/(2y+y)-2=4/3-2=-2/3
-2/3
