12又7分之1 - 6又6分之5 - 3又14分之9

12又7分之1 = 85/7
6又6分之5 = 41/6
3又14分之9 = 51/14

85/7 - 41/6 - 51/14
= 170/14 - 41/6 - 51/14
= 119/14 - 41/6
= 357/42 - 287/42
= 70/42
= 10/6
= 5/3
= 一又三分之二

12又7分之1 - 6又6分之5 - 3又14分之9
=12/1/7 - 6/5/6 - 3/9/14
=85/7 - 41/6 - 51/14
=5/13/42 - 51/14
=223/42 - 51/14
=1/2/3
=1又3分之2

一又三分之二

12又7分之1 - 6又6分之5 - 3又14分之9
先通份母
=12又42分之6 - 6又42分之35 - 3又42分之27
=42分之510-287-153
=42分之70
=21分之35
=1又7分之2

2007-10-26 14:48:01 補充：
sorry ans. is 1又3分之2