Question

x-y分之x^2+y^2+y-x分之2xy

Answer 1

(x²+y²)/(x-y)+2xy/(y-x)

=(x²+y²)/(x-y)-2xy/(x-y)

=(x²+y²-2xy)/(x-y)

=(x-y)²/(x-y)

=x-y

希望采纳!