己知1/a+b=1/a+1/b,求b/a+a/b的值
1/a+b=1/a+1/b 1/a+b=(a+b)/ab ab=(a+b)^2 b/a+a/b =(a^2+b^2)/ab =(a+b)^2-2ab/ab =ab-2ab/ab =-1