17/5*24/9+17/9*24/7谁知道我给高悬赏啊

问题描述:

17/5*24/9+17/9*24/7
谁知道我给高悬赏啊

17/5×24/9+17/9×24/7
=17/9×24/5+17/9×24/7
=17/9×(24/5+24/7)
=17/9×(168/35+120/35)
=17/9×288/35
=544/35