Luyện tập trang 131

$\frac{8}{3} - \frac{5}{3} = \frac{3}{3} = 1$

$\frac{16}{5} - \frac{9}{5} = \frac{7}{5}$

$\frac{21}{8} - \frac{3}{8} = \frac{18}{8} = \frac{9}{4}$

$\frac{3}{4} - \frac{2}{7} = \frac{21}{28} - \frac{8}{28} = \frac{12}{28}$

$\frac{3}{8} - \frac{5}{16} = \frac{6}{16} - \frac{5}{16} = \frac{1}{16}$

$\frac{7}{5} - \frac{2}{3} = \frac{21}{15} - \frac{10}{15} = \frac{11}{15}$

$\frac{31}{36} - \frac{5}{36} = \frac{31}{36} - \frac{30}{36} = \frac{1}{36}$

$2 - \frac{3}{2} = \frac{4}{2} - \frac{3}{2} = \frac{1}{2}$

$5 - \frac{14}{3} = \frac{15}{3} - \frac{14}{3} = \frac{1}{3}$

$\frac{37}{12} - 3 = \frac{37}{12} - \frac{36}{12} = \frac{1}{12}$

$\frac{3}{15} - \frac{5}{35} = \frac{1}{5} - \frac{1}{7} = \frac{7}{35} - \frac{5}{35} = \frac{2}{35}$

$\frac{18}{27} - \frac{2}{6} = \frac{2}{3} - \frac{1}{3} = \frac{1}{3}$

$\frac{15}{25} - \frac{3}{21} = \frac{3}{5} - \frac{1}{7} = \frac{21}{35} - \frac{5}{35} = \frac{16}{35}$

$\frac{24}{36} - \frac{6}{12} = \frac{2}{3} - \frac{1}{2} = \frac{4}{6} - \frac{3}{6} = \frac{1}{6}$

Thời gian ngủ của Nam là:

(ngày)

Đáp số: ngày