1.(-1/3)-(-1/2)+3/4+(-2/3)
=(-1/3-2/3)+(1/2+3/4)
=-1+5/4
=1/4
2.1.36-(-2.64+5.2)-0.2
=(1.36+2.64)-(5.2+0.2)
=4-5.4
=-1.4
3.3又7/45+12又4/13-9又2/5+7又5/26
=(3又7/45-9又2/5)+(12又4/13+7又5/26)
=-6又11/45+19又1/2
=13又23/90
4.-0.5-（-3又1/4）+2.75-（+7又1/2)
=-0.5+3.25+2.75-7.5
=-2
5.5/4+[-2又1/3-(1 又3/4-1又2/3)]
= 5/4-2又1/3-1 又3/4+1又2/3
= (5/4-1又3/4)-(2又1/3-1又2/3)
=-1/2-2/3
=-1又1/6
6.-(-3.21)-(+2.47)-(-1.53)+(+1.29)
=3.21-2.47+1.53+1.29
=3.56