(负0.5)+3又4分之1+2.75+(负7又2分之1)

问题描述:

(负0.5)+3又4分之1+2.75+(负7又2分之1)

(负0.5)+3又4分之1+2.75+(负7又2分之1) =-0.5+3.25+2.75-7.5=(3.25+2.75)-(0.5+7.5)=6-8=-2