1. 直接写出得数。
$\frac{3}{5}÷\frac{2}{3}=$ $\frac{1}{2}×\frac{5}{6}=$ $0.3^{3}=$ $1-\frac{5}{9}+\frac{4}{9}=$
$3-\frac{3}{7}=$ $\frac{3}{11}:\frac{2}{9}=$ $0.25×0.125=$ $2×\frac{2}{3}÷2×\frac{2}{3}=$

$\frac{9}{10}$；$\frac{5}{12}$；$0.027$；$\frac{8}{9}$；$2\frac{4}{7}$；$\frac{27}{22}$；$\frac{1}{32}$；$\frac{4}{9}$

2. 解方程。
$\frac{1}{5}x+\frac{2}{3}x= \frac{16}{15}$ $x+75\% x= 35$ $3-\frac{1}{7}x= \frac{2}{7}$

(1) $\frac{1}{5}x+\frac{2}{3}x= \frac{16}{15}$
解：$\frac{3}{15}x+\frac{10}{15}x=\frac{16}{15}$
$\frac{13}{15}x=\frac{16}{15}$
$x=\frac{16}{13}$
(2)$x+75\% x= 35$
解：$x+\frac{3}{4}x=35$
$\frac{7}{4}x=35$
$x=35×\frac{4}{7}$
$x=20$
(3)$3-\frac{1}{7}x= \frac{2}{7}$
解：$-\frac{1}{7}x= \frac{2}{7}-3$
$-\frac{1}{7}x= \frac{2}{7}-\frac{21}{7}$
$-\frac{1}{7}x= -\frac{19}{7}$
$x=19$

3. 下面各题,怎样算简便就怎样算。
$(\frac{1}{4}+\frac{1}{6})÷\frac{1}{24}$ $\frac{10}{9}×\frac{5}{7}-\frac{1}{9}÷\frac{7}{5}$
$\frac{5}{8}+\frac{2}{17}÷\frac{1}{5}+\frac{7}{17}$ $[\frac{3}{4}-(\frac{5}{8}-\frac{1}{4})]÷\frac{3}{8}$

1. $(\frac{1}{4}+\frac{1}{6})÷\frac{1}{24} = (\frac{1}{4}+\frac{1}{6})×24 = \frac{1}{4}×24+\frac{1}{6}×24 = 6+4 = 10$
2. $\frac{10}{9}×\frac{5}{7}-\frac{1}{9}÷\frac{7}{5} = \frac{10}{9}×\frac{5}{7}-\frac{1}{9}×\frac{5}{7} = (\frac{10}{9}-\frac{1}{9})×\frac{5}{7} = 1×\frac{5}{7} = \frac{5}{7}$
3. $\frac{5}{8}+\frac{2}{17}÷\frac{1}{5}+\frac{7}{17} = \frac{5}{8}+\frac{2}{17}×5+\frac{7}{17} = \frac{5}{8}+\frac{10}{17}+\frac{7}{17} = \frac{5}{8}+(\frac{10}{17}+\frac{7}{17}) = \frac{5}{8}+1 = 1\frac{5}{8}$
4. $[\frac{3}{4}-(\frac{5}{8}-\frac{1}{4})]÷\frac{3}{8} = [\frac{3}{4}-\frac{5}{8}+\frac{1}{4}]÷\frac{3}{8} = [(\frac{3}{4}+\frac{1}{4})-\frac{5}{8}]÷\frac{3}{8} = [1-\frac{5}{8}]÷\frac{3}{8} = \frac{3}{8}×\frac{8}{3} = 1$