1.计算:(+160)+(-90) (1 1/4)+1.25 (-0.5)+4.32.2,1,-5 有理数之和等于()3.如果a=-3,b=-7,则a+b=(),|a|+|b|=( )4.(-3)+()=-12 ()+(-5)=7 (+4)+()=05.如果|x|=2,|y|,=3 x,y同号是,x+y=()或() x,y异号时,x+y=()或()6.直接写出结果:100+(-20) (-8)+8 (-20)+(-15) (-2)+0 (-65)+(+15) 0+(-5)7.计算:(+3/5)+(-7/12) (-3 2/3)+(-1/6) (-0.25)+(+3/4) (+1、579)+(-0.874) 1+(-1/2)+(-1/3) (-1/5)+0+(+8/15)

问题描述:

1.计算:(+160)+(-90) (1 1/4)+1.25 (-0.5)+4.3
2.2,1,-5 有理数之和等于()
3.如果a=-3,b=-7,则a+b=(),|a|+|b|=( )
4.(-3)+()=-12 ()+(-5)=7 (+4)+()=0
5.如果|x|=2,|y|,=3 x,y同号是,x+y=()或() x,y异号时,x+y=()或()
6.直接写出结果:100+(-20) (-8)+8 (-20)+(-15) (-2)+0
(-65)+(+15) 0+(-5)
7.计算:(+3/5)+(-7/12) (-3 2/3)+(-1/6) (-0.25)+(+3/4)
(+1、579)+(-0.874) 1+(-1/2)+(-1/3) (-1/5)+0+(+8/15)