A-A+

计算:(1)(-23)+(-12);(2)6-(3)-(-7)+(-2);(3)-1613+

2022-08-15 11:12:14 问答库 阅读 205 次

问题详情

计算:
(1)(-23)+(-12);
(2)6-(3)-(-7)+(-2);
(3)-161

3

+291

6


(4)-0.5-(-31

4

)+2.75-71

2


(5)-(-7)+(-2);
(6)(-41

4

)-(51

3

)-(-41

4

);
(7)(9)+(-7)+(10)+(-3)+(-9);
(8)1-3+5-7+9-11+…+97-99+100.

参考答案

(1)(-23)+(-12)=-35;

(2)6-(+3)-(-7)+(-2)=6-3+7-2=13-5=8;

(3)-1613+2916=1256;

(4)-0.5-(-314)+2.75-712=-0.5-7.5+3.25+2.75=-8+6=-2;

(5)-(-7)+(-2)=7-2=5;

(6)(-414)-(+513)-(-414)=-414+414-513=-513;

(7)(+9)+(-7)+(+10)+(-3)+(-9)=9-7+10-3-9=0;

(8)1-3+5-7+9-11+…+97-99+100=(1-3)+(5-7)+(9-11)+…+(97-99)+100=-2-2-2-…-2+100=-2×25+100=50.

考点: