题目内容
计算:2010+
-1
+2
-3
+4
-5
+…+2008
-2009
.
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分析:2
-1
=1
,4
-3
=1
,…2008
-2007
=1
,由此进行求解.
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解答:解:2010+
-1
+2
-3
+4
-5
+…+2008
-2009
,
=2010+
+(2
-1
)+(4
-3
)+(2008
-2007
)-2009
,
=(2
-1
)+(4
-3
)+(2008
-2007
)+(2010
-2009
),
=1
+1
+…1
,
=1
×1005,
=1172
.
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=2010+
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=(2
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=1
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=1
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=1172
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点评:本题先求出相邻两个数的差相等,再根据乘法的意义求解.
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