(1) (-8)+10+2+(-1) =2+2+(-1) =4+(-1) =3 (2) 5+(-6)+3+9+(-4)+(-7) =(-1)+3+9+(-4)+(-7) =2+9+(-4)+(-7) =11+(-4)+(-7) =7+(-7) =0 (3) (-0.8)+1.2+(-0.7)+(-2.1)+0.8+3.5 =0.4+(-0.7)+(-2.1)+0.8+3.5 =(-0.3)+(-2.1)+0.8+3.5 =(-0.09)+0.8+3.5 =4.12 (4) 2/1+(-3/2)+
来源:学生作业帮助网 编辑:作业帮 时间:2024/11/05 16:29:06
(1) (-8)+10+2+(-1) =2+2+(-1) =4+(-1) =3 (2) 5+(-6)+3+9+(-4)+(-7) =(-1)+3+9+(-4)+(-7) =2+9+(-4)+(-7) =11+(-4)+(-7) =7+(-7) =0 (3) (-0.8)+1.2+(-0.7)+(-2.1)+0.8+3.5 =0.4+(-0.7)+(-2.1)+0.8+3.5 =(-0.3)+(-2.1)+0.8+3.5 =(-0.09)+0.8+3.5 =4.12 (4) 2/1+(-3/2)+
(1)
(-8)+10+2+(-1)
=2+2+(-1)
=4+(-1)
=3
(2)
5+(-6)+3+9+(-4)+(-7)
=(-1)+3+9+(-4)+(-7)
=2+9+(-4)+(-7)
=11+(-4)+(-7)
=7+(-7)
=0
(3)
(-0.8)+1.2+(-0.7)+(-2.1)+0.8+3.5
=0.4+(-0.7)+(-2.1)+0.8+3.5
=(-0.3)+(-2.1)+0.8+3.5
=(-0.09)+0.8+3.5
=4.12
(4)
2/1+(-3/2)+5/4+(-2/1)+(-3/1)
=30/15+(-30/20)+30/24+(-30/15)+(-30/10)
=(-30/5)+30/24+(-30/15)+(-30/10)
=30/19+(-30/15)+(-30/10)
=30/4+(-30/10)
=-30/6
大家看我做的对么!
(1) (-8)+10+2+(-1) =2+2+(-1) =4+(-1) =3 (2) 5+(-6)+3+9+(-4)+(-7) =(-1)+3+9+(-4)+(-7) =2+9+(-4)+(-7) =11+(-4)+(-7) =7+(-7) =0 (3) (-0.8)+1.2+(-0.7)+(-2.1)+0.8+3.5 =0.4+(-0.7)+(-2.1)+0.8+3.5 =(-0.3)+(-2.1)+0.8+3.5 =(-0.09)+0.8+3.5 =4.12 (4) 2/1+(-3/2)+
(-0.8)+1.2+(-0.7)+(-2.1)+0.8+3.5
=0.4+(-0.7)+(-2.1)+0.8+3.5
=(-0.3)+(-2.1)+0.8+3.5
=(-2.4)+0.8+3.5
=1.9
2/1+(-3/2)+5/4+(-2/1)+(-3/1)
=2/1-3/2+5/4-2/1-3/1
=2/1-2/1-3/2-3/1+5/4
=0-3/2-3/1+5/4
=-6/4-12/4+5/4
=-13/4
(-0.8)+1.2+(-0.7)+(-2.1)+0.8+3.5
=0.4+(-0.7)+(-2.1)+0.8+3.5
=(-0.3)+(-2.1)+0.8+3.5
=(-0.09)+0.8+3.5
=4.12 这个不对应该是
(-0.8)+1.2+(-0.7)+(-2.1)+0.8+3.5
=0.4+(-0.7)+(-2.1)+0.8+3...
全部展开
(-0.8)+1.2+(-0.7)+(-2.1)+0.8+3.5
=0.4+(-0.7)+(-2.1)+0.8+3.5
=(-0.3)+(-2.1)+0.8+3.5
=(-0.09)+0.8+3.5
=4.12 这个不对应该是
(-0.8)+1.2+(-0.7)+(-2.1)+0.8+3.5
=0.4+(-0.7)+(-2.1)+0.8+3.5
=(-0.3)+(-2.1)+0.8+3.5
=(-2.4)+0.8+3.5
=(-1.6)+3.5
=1.9
2/1+(-3/2)+5/4+(-2/1)+(-3/1)
=30/15+(-30/20)+30/24+(-30/15)+(-30/10)
=(-30/5)+30/24+(-30/15)+(-30/10)
=30/19+(-30/15)+(-30/10)
=30/4+(-30/10)
=-30/6
这个也不对,第二步就错了,其实这道题可以通过移项解决
2/1+(-3/2)+5/4+(-2/1)+(-3/1)
=2/1+(-2/1)+(-3/2)+(-3/1)+5/4
=0+(-3/2)+(-6/2)+5/4
=(-9/2)+5/4
=(-18/4)+5/4
=-13/4
收起
对了`诶```
第(1)(2)对了
第(3)(4)错了
(3)
(-0.8)+1.2+(-0.7)+(-2.1)+0.8+3.5
=0.4+(-0.7)+(-2.1)+0.8+3.5
=(-0.3)+(-2.1)+0.8+3.5
=(-2.4)+0.8+3.5
=(-1.6)+3.5
=1.9
(4)
2/1+(-3/2)...
全部展开
第(1)(2)对了
第(3)(4)错了
(3)
(-0.8)+1.2+(-0.7)+(-2.1)+0.8+3.5
=0.4+(-0.7)+(-2.1)+0.8+3.5
=(-0.3)+(-2.1)+0.8+3.5
=(-2.4)+0.8+3.5
=(-1.6)+3.5
=1.9
(4)
2/1+(-3/2)+5/4+(-2/1)+(-3/1)
=30/15+(-30/20)+30/24+(-30/15)+(-30/10)
=(-30/5)+30/24+(-30/15)+(-30/10)
=30/19+(-30/15)+(-30/10)
=30/4+(-30/10)
=-30/6
=-5/1
收起