Tính. 2/3x7/10

a) $\frac{2}{3}\times \frac{7}{10}=\mathrm{...............}$

c) $\frac{3}{8}\times \frac{3}{4}=\mathrm{...............}$

b) $\frac{1}{2}\times \frac{5}{6}=\mathrm{...............}$

d) $\frac{1}{5}\times \frac{10}{7}=\mathrm{...............}$

a) $\frac{2}{3}\times \frac{7}{10}=\frac{2\times 7}{3\times 10}=\frac{14}{30}=\frac{7}{15}$

c) $\frac{3}{8}\times \frac{3}{4}=\frac{3\times 3}{8\times 4}=\frac{9}{32}$

b) $\frac{1}{2}\times \frac{5}{6}=\frac{1\times 5}{2\times 6}=\frac{5}{12}$

d) $\frac{1}{5}\times \frac{10}{7}=\frac{1\times 10}{5\times 7}=\frac{10}{35}=\frac{2}{7}$