首页 > 计算：123+234+345+…+199419951996+199519961997313+524+735+…+398919941996+399119951997=______．-数学

计算：123+234+345+…+199419951996+199519961997313+524+735+…+398919941996+399119951997=______．-数学

题目简介

计算：123+234+345+…+199419951996+199519961997313+524+735+…+398919941996+399119951997=______．-数学

题目详情

计算：
1
2
3
+2
3
4
+3
4
5
+…+1994
1995
1996
+1995
1996
1997
3
1
3
+5
2
4
+7
3
5
+…+3989
1994
1996
+3991
1995
1997
=______．
题型：填空题难度：中档来源：不详

答案

1class="stub"2
3
+2class="stub"3
4
+3class="stub"4
5
+…+1994class="stub"1995
1996
+1995class="stub"1996
1997
3class="stub"1
3
+5class="stub"2
4
+7class="stub"3
5
+…+3989class="stub"1994
1996
+3991class="stub"1995
1997

=
(2-class="stub"1
3
)+(3-class="stub"1
4
)+(4-class="stub"1
5
)++(1995-class="stub"1
1996
)+(1996-class="stub"1
1997
)
(4-class="stub"2
3
)+(6-class="stub"2
4
)+(8-class="stub"2
5
)++(3990-class="stub"2
1996
)+(3992-class="stub"2
1997
)

=class="stub"1
2
．
故答案为：class="stub"1
2
．

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