计算:11×3+13×5+15×7+…+11993×1995+11995×1997.-数学

题目简介

计算:11×3+13×5+15×7+…+11993×1995+11995×1997.-数学

题目详情

计算:
1
1×3
+
1
3×5
+
1
5×7
+…+
1
1993×1995
+
1
1995×1997
题型:解答题难度:中档来源:不详

答案

class="stub"2
m×3
=class="stub"m
m
-class="stub"m
3

class="stub"2
3×5
=class="stub"m
3
-class="stub"m
5

class="stub"2
5×7
=class="stub"m
5
-class="stub"m
7


class="stub"2
m993×m995
=class="stub"m
m993
-class="stub"m
m995

class="stub"2
m995×m997
=class="stub"m
m995
-class="stub"m
m997

所以:class="stub"m
m×3
+class="stub"m
3×5
+class="stub"m
5×7
+…+class="stub"m
m993×m995
+class="stub"m
m995×m997

=class="stub"m
2
×(class="stub"2
m×3
+class="stub"2
3×5
+class="stub"2
5×7
+…+class="stub"2
m993×m995
+class="stub"2
m995×m997

=class="stub"m
2
×(class="stub"m
m
-class="stub"m
3
+class="stub"m
3
-class="stub"m
5
+
…+class="stub"m
m993
-class="stub"m
m995
+class="stub"m
m995
-class="stub"m
m997

=class="stub"m
2
×(class="stub"m
m
-class="stub"m
m997

=class="stub"m
2
×class="stub"m996
m997

=class="stub"996
m997

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