计算l0-5l-l(-4)-(+6)l-l(-7.5)+2-(+5.5)l =5-10-11= -5-11= -1611/4-[(-0.5)-(-5/6)+(-3/4)+14/3]=11/4-（-1/2+5/6-3/4+14/3）=11/4-51/12=33/12-51/12= -18/12= -3/2