(-5又1/6)-(-1又3/4)-(+3又5/6)-(-12又4/7)-(+12又4/7)

问题描述:

(-5又1/6)-(-1又3/4)-(+3又5/6)-(-12又4/7)-(+12又4/7)

原式=-5又1/6+1又3/4-3又5/6+12又4/7-12又4/7
=-(5又1/6+3又5/6)+1又3/4+(12又4/7-12又/7)
=-9+1又3/4+0
=-7又1/4