(十二分之五减七分之三)减(七分之四减十二分之七)等于几

问题描述:

(十二分之五减七分之三)减(七分之四减十二分之七)等于几

(5/12-3/7)-(4/7-7/12)
=5/12-3/7-4/7+7/12
=5/12+7/12-(3/7+4/7)
=1-1
=0