原式=(-3.75)+2.85+(-1又1/4)+(-1/2)+3.5+(-2.5)=-3.75+2.85-1.25-0.5+3.5-2.5=(2.85+3.5)-(3.75+1.25+0.5+2.5)=6.35-8=-(8-6.35)=-1.65
-3.15
