Giải câu 1 trang 10 VBT toán 5 tập 1

a) $\frac{5}{9}$ x $\frac{12}{7}$ = $\frac{5 \times 12}{9 \times 7}$ = $\frac{60}{63}$ = $\frac{20}{21}$

b) $\frac{6}{5}$ : $\frac{8}{3}$ = $\frac{6}{5}$ x $\frac{3}{8}$ = $\frac{18}{40}$ = $\frac{9}{20}$

c) $\frac{9}{20}$ x $\frac{5}{12}$ = $\frac{9 \times 5}{20 \times 12}$ = $\frac{45}{240}$ = $\frac{3}{16}$

d) $\frac{15}{16}$ : $\frac{25}{24}$ = $\frac{15}{16}$ x $\frac{24}{25}$ = $\frac{360}{400}$ = $\frac{9}{10}$

e) 14 x $\frac{5}{21}$ = $\frac{14 \times 5}{21}$ = $\frac{70}{21}$ = $\frac{10}{3}$

g) 10 : $\frac{5}{3}$ = $\frac{10}{1}$ x $\frac{5}{3}$ = $\frac{30}{5}$ = 6

h) $\frac{5}{3}$ : 10 = $\frac{5}{3}$ x $\frac{1}{10}$ = $\frac{5}{30}$ = $\frac{1}{6}$