(1) (x^-1)+(y^-1)分之(x^-2)-(y^-2) (2) (y-x^-1)除以(x-y^-1) 一共两道题目怎么做

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/29 23:52:47

(1) (x^-1)+(y^-1)分之(x^-2)-(y^-2) (2) (y-x^-1)除以(x-y^-1) 一共两道题目怎么做
(1) (x^-1)+(y^-1)分之(x^-2)-(y^-2) (2) (y-x^-1)除以(x-y^-1) 一共两道题目怎么做

(1) (x^-1)+(y^-1)分之(x^-2)-(y^-2) (2) (y-x^-1)除以(x-y^-1) 一共两道题目怎么做
(1)
原式=(1/x+1/y)/(1/x²-1/y²)
=(1/x+1/y)/[(1/x+1/y)(1/x-1/y)]
=1/(1/x-1/y)
=xy/(y-x)
(2)
原式=(y-1/x)/(x-1/y)
=[(xy-1)/x]/[(xy-1)/y]
=(1/x)/(1/y)
=y/x