计算,把结果写成若干个分母是质数的既约分数之和:19+59-119+195-11995=______.-数学

题目简介

计算,把结果写成若干个分母是质数的既约分数之和:19+59-119+195-11995=______.-数学

题目详情

计算,把结果写成若干个分母是质数的既约分数之和:
1
9
+
5
9
-
1
19
+
1
95
-
1
1995
=______.
题型:填空题难度:中档来源:不详

答案

class="stub"1
9
+class="stub"5
9
-class="stub"1
19
+class="stub"1
95
-class="stub"1
1995

=class="stub"6
9
-class="stub"105-21+1
1995

=class="stub"2
3
-
class="stub"17
399

=class="stub"83
133

133=7×19,
class="stub"83
133
=class="stub"a
7
+class="stub"b
19

则19×a+7×b=83,易见a=4,b=1,符合要求.
所以,class="stub"1
9
+class="stub"5
9
-class="stub"1
19
+class="stub"1
95
-class="stub"1
1995
=class="stub"4
7
+class="stub"1
19

故答案为:class="stub"4
7
+class="stub"1
19

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