(一又四分之三减零点八七五减十二分之七)乘(负一又七分之一)
=(1又3/4-7/8-7/12)×(-1又1/7)
=(7/4-7/8-7/12)×(-8/7)
=[7/4+(-7/8)+(-7/12)]×(-8/7)
=7/4×(-8/7)+(-7/8)×(-8/7)+(-7/12)×(-8/7)
= -2+1+2/3
= -2+5/3
= -6/3+5/3
= -1/3