1.直接写出得数。（每题1★）
$\frac{5}{8} ÷ \frac{15}{16} =$
$\frac{1}{2} ÷ \frac{4}{15} =$
$\frac{5}{8} ÷ \frac{9}{4} =$
$16 ÷ \frac{4}{7} =$
$\frac{2}{15} ÷ \frac{1}{3} =$
$\frac{3}{4} ÷ \frac{3}{4} =$
$\frac{2}{3} ÷ \frac{1}{3} =$
$\frac{1}{10} ÷ \frac{8}{21} =$
$\frac{5}{8} ÷ \frac{3}{8} =$
$\frac{3}{5} × \frac{10}{9} =$
$\frac{7}{11} ÷ \frac{7}{9} =$
$\frac{2}{21} ÷ \frac{6}{7} =$
$\frac{8}{15} × \frac{5}{2} =$
$\frac{7}{26} ÷ \frac{21}{13} =$
$\frac{5}{33} ÷ \frac{5}{22} =$
$\frac{3}{5} × \frac{7}{12} =$
$\frac{1}{5} ÷ \frac{7}{10} =$
$\frac{5}{8} ÷ \frac{1}{6} =$
$\frac{1}{5} ÷ \frac{4}{3} =$
$\frac{7}{9} ÷ \frac{7}{18} =$

$\frac{2}{3}$ $\frac{15}{8}$ $\frac{5}{18}$ 28
$\frac{2}{5}$ 1 2 $\frac{21}{80}$
$\frac{5}{3}$ $\frac{2}{3}$ $\frac{9}{11}$ $\frac{1}{9}$
$\frac{4}{3}$ $\frac{1}{6}$ $\frac{2}{3}$ $\frac{7}{20}$
$\frac{2}{7}$ $\frac{15}{4}$ $\frac{3}{20}$ 2

2.计算下面各题。(写出计算过程)(每题 3★)
$\frac{16}{25}÷\frac{8}{15}$
$\frac{1}{5}÷\frac{15}{28}$
$\frac{7}{81}÷\frac{5}{12}$

$\frac{6}{5}$ $\frac{28}{75}$ $\frac{28}{135}$(计算过程略)

3.解方程。（每题3★）
$\frac{4}{5}x=\frac{16}{35}$
$\frac{4}{7}x=10$
$\frac{7}{11}x=42$
$\frac{1}{4}x=23$
$\frac{4}{5}x=\frac{8}{15}$
$\frac{8}{15}x=\frac{2}{5}$

$x=\frac{4}{7}$ $x=\frac{35}{2}$ $x=66$
$x=92$ $x=\frac{2}{3}$ $x=\frac{3}{4}$