解答下列各题:(1)(-12)-5+(-14)-(-39)(2)312-(-13)+223+(-12)(3)25-|-112|-(+214)-(-2.75)(4)(-1)+2+(-3)+4+…+(-9

题目简介

解答下列各题:(1)(-12)-5+(-14)-(-39)(2)312-(-13)+223+(-12)(3)25-|-112|-(+214)-(-2.75)(4)(-1)+2+(-3)+4+…+(-9

题目详情

解答下列各题:
(1)(-12)-5+(-14)-(-39)
(2)3
1
2
-(-
1
3
)+2
2
3
+(-
1
2
)

(3)
2
5
-|-1
1
2
|-(+2
1
4
)-(-2.75)

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

答案

(1)原式=-12-5-14+39=-31+39=8;
(2)原式=(3class="stub"1
2
-class="stub"1
2
)+(class="stub"1
3
+2class="stub"2
3
)=3+3=6;
(3)原式=class="stub"2
5
-1class="stub"1
2
-2class="stub"1
4
+2.75=class="stub"2
5
-1class="stub"1
2
+class="stub"1
2
=class="stub"2
5
-1=-class="stub"3
5

(4)原式=(-1+2)+(-3+4)+…+(-99+100)=50.

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