x1，x2，x3合力做一工程需花n個小時，x2和x3合力做此工程要花m個小時，若rate不變，
問x1單獨做需多久時間
請問這一題該怎麼算?
--
In fearful day, in raging night,
With strong hearts full, our souls ignite,
When all seems lost in the War of Light,
Look to the stars-- For hope burns bright!
--
問x1單獨做需多久時間
請問這一題該怎麼算?
--
In fearful day, in raging night,
With strong hearts full, our souls ignite,
When all seems lost in the War of Light,
Look to the stars-- For hope burns bright!
--
All Comments