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電子課本網(wǎng) 第64頁

第64頁

信息發(fā)布者:
A
?$12÷130=\frac {6}{65}$?
答:本紀的篇數(shù)是全書總篇數(shù)的?$\frac {6}{65}。$?
?$70÷8=8\frac {3}{4} $?
答:列傳的篇數(shù)是書的篇數(shù)的?$8\frac {3}{4}。$?
B


答:樂樂填的對。?$\frac {1}{6}=\frac {2}{12},$??$\frac {1}{7}=\frac {2}{14},$?因為?$\frac {2}{14}<\frac {2}{13}<\frac {2}{12},$?所以?$\frac {1}{7}<\frac {2}{13}<\frac {1}{6}。$?
答:她的推測正確。?$\frac {1}{a}=\frac {2}{2a},$??$\frac {1}=\frac {2}{26},$?因為?$a>b>0,$?所以?$2b<a+b<2a,$?所以
?$\frac {2}{2a}<\frac {2}{a+b}<\frac {2}{2b},$?也就是?$\frac {1}{a}<\frac {2}{a+b}<\frac {1}。$?