12 9 7 15 13怎麼等於70
[13-9/(15-12)]*7=70
(7分之1+5分之4+35分之12)×9分之7等於多少?簡便運算
(1/7+4/5+12/35)x7/9
同分得
(5/35+28/35+12/35)x7/9
=45/35x7/9
=5/5=1
24分之15乘35分之12等於多少
15/24*12/35
=5/8*12/35
=5/8*3*4/5*7
=3/2*7
=3/14