(-81)除2又4分之1+9分之4除(-16)= 2分之1-{4分之3-(4分之1-5-2分之1)}= 13+(+7)-(-20)-(-40)-急13+(+7)-(-20)-(-40)-(+6)=

问题描述:

(-81)除2又4分之1+9分之4除(-16)= 2分之1-{4分之3-(4分之1-5-2分之1)}= 13+(+7)-(-20)-(-40)-

13+(+7)-(-20)-(-40)-(+6)=

(-81)÷2又1/4+4/9÷(-16)
=-81÷9/7-1/36
=-63-1/36
=-63又1/36
1/2-{3/4-(1/4-5-1/2)}
=1/2-3/4-5-1/2
=-5又3/4
13+(+7)-(-20)-(-40)-(+6)
=13+7+20+20-6
=54