(a+m)/(b+m)=[a+(a/b+(b-a)/b)m]/(b+m)
=(a+am/b)/(b+m)+(b-a)/bm(b+m)
=(a/b)(b+m)/(b+m)+(b-a)/bm(b+m)
=a/b+(b-a)/bm(b+m)
因为b>a>0,m>0,所以(b-a)/bm(b+m)>0
所以原式>a/b,即(a+m)/(b+m)>a/
(a+m)/(b+m)=[a+(a/b+(b-a)/b)m]/(b+m)
=(a+am/b)/(b+m)+(b-a)/bm(b+m)
=(a/b)(b+m)/(b+m)+(b-a)/bm(b+m)
=a/b+(b-a)/bm(b+m)
因为b>a>0,m>0,所以(b-a)/bm(b+m)>0
所以原式>a/b,即(a+m)/(b+m)>a/