已知x=2009,y=2010.化简(x+y)*(x^2+y^2/x^4-y^4)
问题描述：
已知x=2009,y=2010.化简(x+y)*(x^2+y^2/x^4-y^4)
答
(x+y)(x²+y²)/(x^4-y^4)=(x+y)(x²+y²)/(x²+y²)(x²-y²)=(x+y)/(x²-y²)=(x+y)/(x+y)(x-y)=1/(x-y)=1/(2009-2010)=-1谢啦