问题描述: 计算:(x^3+x^2y) / (x^2-y^3) - x(x-y)/ (xy+x^2)- (2xy)/(x^2-y^2) 1个回答 分类:数学 2014-12-13 问题解答: 我来补答 [(x^3+x^2y)/(x^2y-y^3)]-{[x(x-y)]/(xy+x^2)}-[(2xy)/(x^2-y^2)] 原式=[x^2(x+y)/y(x+y)(x-y))]-[x(x-y)]/[x(y+x)]-[2xy/(x+y)(x-y)]=[x^2/y(x-y)]-(x-y)/(x+y)-2xy/(x+y)(x-y)=[x^2(x+y)-y(x-y)^2-2xy^2]/y(x+y)(x-y)=(x^3+x^2y-x^2y+2xy^2-y^3-2xy^2)/y(x+y)(x-y)=(x^3-y^3)/y(x+y)(x-y)=(x-y)(x^2+xy+y^2)/y(x+y)(x-y)=(x^2+xy+y^2)/y(x+y) 展开全文阅读