8道简便计算题 现在要15+(-20)+6+(-8)(-7)+8+3+(-6)+(-5)+93 又3/5+4又8/5+(
1个回答

15+(-20)+6+(-8)

=(15+6)-(20+8)

=21-28

=-7

(-7)+8+3+(-6)+(-5)+9

=(8+3+9)-(7+6+5)

=20-18

=2

3 又3/5+4又8/5+(-5又2/3)+(-1/3)

=9又1/5-6

=3又1/5

(-0.5)+2又1/4+(-9又1/2)+9.75

=(2.25+9.75)-(0.5+9.5)

=12-10

=2

-19+28+19+(-8)

=(19-19)+(28-8)

=8

9+(-7)+10+(-3)+(-9)

=(9-9)+(10-7-3)

=0

0.36+(-7.4)+0.3(-0.6)+0.64

缺符号?0.3(-0.6)

3又1/4+(-5又2/3)+5又3/4+(-8又2/5)

=(3又1/4+5又3/4)-(5又2/3+8又2/5)

=9-14又1/15

=-5又1/15