1、(-72)-(-37)-(-22)-17
=-72+37+22-17
=(37+22)-(72+17)
=59-89
=-30
2、(-16)-(-12)-24-(-18)
=-16+12-24+18
=(12+18)-(16+24)
=30-40
=-10
3、1/2-(-0.25)-1/6
=1/2+1/4-1/6
=1/2-1/6+1/4
=1/3+1/4
=7/12
4、1/3+(-5/6)-(-1/2)-2/3
=1/3-5/6+1/2-2/3
=(1/3-2/3)+(1/2-5/6)
=-1/3-1/3
=-2/3