=5+(-5+20)
=5+15
=20
(-30)+(-15)+(-68),
=-(30+15+68)
=-113
0+(-3.65)+(+2.75)+(-2.5),
=0-3.65+2.75-2.5
=-3.65+(2.75-2.5)
=-3.65+0.25
=-(3.65-0.25)
=-3.4
(-七又七分之二)+(+二又三分之二)+(+四又七分之三)+(-四又三分之壹),
=(4又3/7-7又2/7)+(2又2/3-4又1/3)
=(-2又6/7)+(-1又2/3)
=-(2又6/7+1又2/3)
=-4又11/28
(-三分之二)+(二分之壹)+(-六分之五)+(-三分之壹),
=-(2/3+1/3)+(1/2-5/6)
=-1-1/3
=-(1+1/3)
=-1又1/3
(-四又二分之壹)+{三又五分之二+(-0.13)+0.33},
=-(4又1/2-3又2/5)+(0.33-0.13)
=-1又1/10+0.2
=-(1又1/10-1/5)
=-9/10
5+{+4+3+7+(4+5)+6},
=5+4+3+7+9+6
=34