第一题2xy/x-y+2y平方/y-x 第二题（x - 知识问答

第一题2xy/x-y+2y平方/y-x 第二题（x+y）乘以x平方/x平方-y平方+y平方/y-x 第三题x-2/1-x

1个回答

(1)2xy/x-y+2y^2/y-x
=2y(x-y)/x-y
=2y
(2)(x+y)*x^2/x^2-y^2+y^2/y-x
=(x+y)*x^2/(x+y)(x-y)+y^2/y-x
=x^2/x-y-y^2/x-y
=x^2-y^2/x-y
=x+y
(3)x-2/(1-x)+3x/x^2-x
=[-x+2/x-1]+3/x-1
=5-x/x-1

相关问题