=5+(-5+20)
=5+ 15
=20
(-30)+(- 15)+(-68),
=-(30+ 15+68)
=- 1 13
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
(-7 and 2/7)+(+2 and 2/3)+(+4 and 3/7)+(-4 and 1/3),
=(4 3/7-7 2/7)+(2 2/3-4 1/3)
=(-2 6/7)+(- 1 2/3)
=-(2 6/7+ 1 2/3)
=-4 and 1 1/28
(-two thirds)+(half)+(-five sixths)+(-one third),
=-(2/3+ 1/3)+( 1/2-5/6)
=- 1- 1/3
=-( 1+ 1/3)
=- 1 and 1/3
(-four and a half)+{three fifths +(-0. 13)+0.33},
=-(4 1/2-3 2/5)+(0.33-0. 13)
=- 1 and110+0.2
=-( 1 and110-1/5)
=-9/ 10
5+{+4+3+7+(4+5)+6},
=5+4+3+7+9+6
=34