29.Is (a+b)/(c+d) < a/c+b/d?
1) a,b,c,d all positive
2) a,b,c,d all none zero a+c not equal to 0
(a+b)/(c+d) < a/c+b/d is equal to -(ad2+bc2)/[cd(c+d)]<0,
in 1), it is sufficient, but 2) is not.
Welcome to discuss.
欢迎光临 国际顶尖MBA申请交流平台--TOPWAY MBA (http://forum.topway.org/) | Powered by Discuz! 7.2 |