计算:(1)(-2)+3+1+(-3)+2+(-4);(2)25+211+(-25);(3)(-423+(-313)+612+(-214);(4)(+1)+(-2)+(+3)+(-4)+…+(+99)

题目简介

计算:(1)(-2)+3+1+(-3)+2+(-4);(2)25+211+(-25);(3)(-423+(-313)+612+(-214);(4)(+1)+(-2)+(+3)+(-4)+…+(+99)

题目详情

计算:
(1)(-2)+3+1+(-3)+2+(-4);
(2)
2
5
+
2
11
+(-
2
5
);
(3)(-4
2
3
+(-3
1
3
)+6
1
2
+(-2
1
4
);
(4)(+1)+(-2)+(+3)+(-4)+…+(+99)+(-100).
题型:解答题难度:中档来源:不详

答案

(1)(-2)+3+1+(-3)+2+(-4)=-2+3+1-3+2-4=1-4=-3;

(2)class="stub"2
5
+class="stub"2
11
+(-class="stub"2
5
)=class="stub"2
5
-class="stub"2
5
+class="stub"2
11
=class="stub"2
11


(3)(-4class="stub"2
3
)+(-3class="stub"1
3
)+6class="stub"1
2
+(-2class="stub"1
4
)=-4class="stub"2
3
-3class="stub"1
3
+6class="stub"1
2
-2class="stub"1
4
=6class="stub"1
2
-10class="stub"1
4
=-3class="stub"3
4


(4)(+1)+(-2)+(+3)+(-4)+…+(+99)+(-100)=(1-2)+(3-4)+(5-6)+…+(99-100)=-1-1-1-…-1=-50.

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