若xy=1,则(x+1分之1)+(y+1分之一)=?

问题描述:

若xy=1,则(x+1分之1)+(y+1分之一)=?

(x+1分之1)+(y+1分之一)
=(y+1+x+1)/(x+1)(y+i)
=x+y+2/(xy+x+y+1)
=x+y+2/(1+x+y+1)
=1