电子课本网 第57页

第57页

信息发布者:
​$\frac {1}{6}$​
+
​$\frac {5}{6}$​
-
​$\frac {1}{9}$​
+
​$\frac {2}{9}$​
+
-
+
​$=\frac {4}{7}-\frac {3}{7}+\frac {1}{6}$​
​$=\frac {1}{7}+\frac {1}{6}$​
​$=\frac {13}{42}$​
​$=2-(\frac {7}{9}+\frac {2}{9})$​
​$=2-1$​
​$=1$​
​$=\frac {1}{4}+\frac {3}{4}+\frac {2}{5}$​
​$=1+\frac {2}{5}$​
​$=1 \frac {2}{5}$​
​$=\frac {3}{5}+\frac {2}{5}+\frac {7}{8}$​
​$=1+\frac {7}{8}$​
​$=1 \frac {7}{8}$​
​$=\frac {7}{9}-\frac {1}{9}-\frac {1}{3}$​
​$=\frac {2}{3}-\frac {1}{3}$​
​$=\frac {1}{3}$​
$=\frac {5}{6}+\frac {1}{6}-(\frac {3}{10}+\frac {3}{10})$
$=\frac {5}{6}+\frac {1}{6}-\frac {3}{5}$
$=1-\frac {3}{5}$
$= \frac {2}{5}$

​$(1)1-\frac {1}{5}-\frac {1}{10}=\frac {7}{10}$​
答:还剩下总数的​$\frac {7}{10}.$​
$(2)\frac {1}{2}-\frac {1}{5}-\frac {1}{10}=\frac {1}{5}($吨)
答:还剩下$\frac {1}{5}$吨没有卖出.
​$\frac {2}{5}+\frac {1}{10}=\frac {1}{2}$​
答:第二天修了全长的​$\frac {1}{2}。$​
​$10÷2=5 ($​千米)
答:第二天修了​$5$​千米。
第一天吃了总数的​$\frac {1}{7},$​还剩下总数的​$\frac {6}{7};$​
第二天吃了剩下的一半,是总数的​$\frac {3}{7},$​则有
​$1-\frac {1}{7}-\frac {3}{7}=\frac {3}{7}$​
答:这些桃还剩下总数的​$\frac {3}{7}.$​