分母是21,且大小在-23和-13之间的分数有______个,分母是10,且大小在-23和-13之间的分数是______.-数学

题目简介

分母是21,且大小在-23和-13之间的分数有______个,分母是10,且大小在-23和-13之间的分数是______.-数学

题目详情

分母是21,且大小在-
2
3
和-
1
3
之间的分数有 ______个,分母是10,且大小在-
2
3
和-
1
3
之间的分数是 ______.
题型:填空题难度:偏易来源:不详

答案

-class="stub"2
3
和-class="stub"1
3
通分后变为-class="stub"14
21
和-class="stub"7
21

则分母为21且在-class="stub"14
21
和-class="stub"7
21
之间的分数为-class="stub"13
21
,-class="stub"12
21
,-class="stub"11
21
,-class="stub"10
21
,-class="stub"9
21
,-class="stub"8
21
,共6个;
分母是10的负真分数为-class="stub"1
10
,-class="stub"2
10
,-class="stub"3
10
,-class="stub"4
10
,-class="stub"5
10
,-class="stub"6
10
,-class="stub"7
10
,-class="stub"8
10
,-class="stub"9
10

-class="stub"2
3
和-class="stub"1
3
变为分母是30的分数后为-class="stub"20
30
和-class="stub"10
30

负真分数-class="stub"1
10
,-class="stub"2
10
,-class="stub"3
10
,-class="stub"4
10
,-class="stub"5
10
,-class="stub"6
10
,-class="stub"7
10
,-class="stub"8
10
,-class="stub"9
10
变为分母是30的分数为:-class="stub"3
30

-class="stub"6
30
,-class="stub"9
30
,-class="stub"12
30
,-class="stub"15
30
,-class="stub"18
30
,-class="stub"21
30
,-class="stub"24
30
,-class="stub"27
30

故在-class="stub"20
30
和-class="stub"10
30
之间的负真分数为-class="stub"12
30
,-class="stub"15
30
,-class="stub"18
30
即-class="stub"4
10
,-class="stub"5
10
,-class="stub"6
10

故答案为:6;-class="stub"4
10
,-class="stub"5
10
,-class="stub"6
10

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