Выполни умножение: 1) 4/5 · 1/4; 2) 6/7 · 7/9; 3) 5/7 · 5/13; 4) 4/13 · 5/11; 5) 1/10 · 2/9; 6) 15/16 · 20/21; 7) 9/13 · 9/13; 8) 3/10 · 9/10.

\(\frac{4}{5}\cdot\frac{1}{4}=\frac{1}{5}\).

\(\frac{6}{7}\cdot\frac{7}{9}=\frac{6}{9}=\frac{2}{3}\).

\(\frac{5}{7}\cdot\frac{5}{13}=\frac{25}{91}\).

\(\frac{4}{13}\cdot\frac{5}{11}=\frac{20}{143}\).

\(\frac{1}{10}\cdot\frac{2}{9}=\frac{2}{90}=\frac{1}{45}\).

\(\frac{15}{16}\cdot\frac{20}{21}=\frac{300}{336}=\frac{25}{28}\).

\(\frac{9}{13}\cdot\frac{9}{13}=\frac{81}{169}\).

\(\frac{3}{10}\cdot\frac{9}{10}=\frac{27}{100}\).