a) \(\frac{{ - 2}}{7}:\frac{4}{7} = \frac{{ - 2}}{7}.\frac{7}{4} = \frac{{ - 2}}{4} = \frac{{ - 1}}{2}\)      

b) \(\frac{{ - 4}}{5}:\frac{{ - 3}}{{11}} = \frac{{ - 4}}{5}.\frac{{11}}{{ - 3}} = \frac{{ - 44}}{{ - 15}} = \frac{{44}}{{15}}\)

c) \(4:\frac{{ - 2}}{5} = 4.\frac{5}{{ - 2}} = \frac{{20}}{{ - 2}} =  - 10\)

d) \(\frac{{15}}{{ - 8}}:6 = \frac{{15}}{{ - 8}}.\frac{1}{6} = \frac{{ - 15}}{{48}}= \frac{{ - 5}}{{16}}\).

a) \(\dfrac{-2}{7}:\dfrac{4}{7}=\dfrac{-2}{7}.\dfrac{7}{4}=\dfrac{-2.7}{7.4}=\dfrac{-1}{2}\)

b) \(\dfrac{-4}{5}:\dfrac{-3}{11}=\dfrac{-4}{5}.\dfrac{-11}{3}=\dfrac{-4.\left(-11\right)}{5.3}=\dfrac{44}{15}\)

c) \(4:\dfrac{-2}{5}=4.\dfrac{-5}{2}=\dfrac{4.\left(-5\right)}{2}=-10\)

d) \(\dfrac{15}{-8}:6=\dfrac{-15}{8}.\dfrac{1}{6}=\dfrac{-15}{8.6}=\dfrac{-5}{16}\)

a) \(\dfrac{3}{5}:\dfrac{3}{4}=\dfrac{3}{5}\cdot\dfrac{4}{3}=\dfrac{4}{5}\)

b) \(\dfrac{2}{5}:\dfrac{3}{10}=\dfrac{2}{5}\cdot\dfrac{10}{3}=\dfrac{4}{3}\)

c) \(\dfrac{1}{8}:\dfrac{1}{6}=\dfrac{1}{8}\cdot6=\dfrac{6}{8}=\dfrac{3}{4}\)

a: \(=\dfrac{3}{5}\cdot\dfrac{4}{3}=\dfrac{12}{15}=\dfrac{4}{5}\)

b: \(=\dfrac{2}{5}\cdot\dfrac{10}{3}=\dfrac{20}{15}=\dfrac{4}{3}\)

c: \(=\dfrac{1}{8}\cdot6=\dfrac{6}{8}=\dfrac{3}{4}\)

a, \(\dfrac{3}{5}:\dfrac{3}{4}=\dfrac{3}{5}x\dfrac{4}{3}=\dfrac{12}{15}\)

b, \(\dfrac{2}{5}:\dfrac{3}{10}=\dfrac{2}{5}x\dfrac{10}{3}=\dfrac{4}{3}\)

c, \(\dfrac{1}{8}:\dfrac{1}{6}=\dfrac{1}{8}x\dfrac{6}{1}=\dfrac{3}{4}\)

a) $\frac{1}{6}:\frac{3}{7} = \frac{1}{6} \times \frac{7}{3} = \frac{7}{{18}}$  

b) $\frac{5}{{12}}:\frac{1}{4} = \frac{5}{{12}} \times \frac{4}{1} = \frac{{5 \times 4}}{{12 \times 1}} = \frac{{5 \times 4}}{{4 \times 3 \times 1}} = \frac{5}{3}$

c) $\frac{4}{{15}}:\frac{8}{3} = \frac{4}{{15}} \times \frac{3}{8} = \frac{{4 \times 3}}{{15 \times 8}} = \frac{{4 \times 3}}{{5 \times 3 \times 4 \times 2}} = \frac{1}{{10}}$          

d) $\frac{{18}}{5}:\frac{9}{{10}} = \frac{{18}}{5} \times \frac{{10}}{9} = \frac{{18 \times 10}}{{5 \times 9}} = \frac{{9 \times 2 \times 5 \times 2}}{{5 \times 9}} = 4$

a) \(\dfrac{2}{4}\times\dfrac{9}{5}=\dfrac{1}{2}\times\dfrac{9}{5}=\dfrac{1\times9}{2\times5}=\dfrac{9}{10}\)

b) \(\dfrac{13}{8}\times\dfrac{5}{15}=\dfrac{13}{8}\times\dfrac{1}{3}=\dfrac{13}{24}\)

c) \(\dfrac{3}{9}\times\dfrac{6}{12}=\dfrac{1}{3}\times\dfrac{1}{2}=\dfrac{1}{3\times2}=\dfrac{1}{6}\)

a: =18/20=9/10

b: \(=\dfrac{13\cdot5}{8\cdot15}=\dfrac{13}{8}\cdot\dfrac{1}{3}=\dfrac{13}{24}\)

c: \(=\dfrac{1}{3}\cdot\dfrac{1}{2}=\dfrac{1}{6}\)

a) $\frac{1}{6} \times \frac{2}{3} = \frac{{1 \times 2}}{{6 \times 3}} = \frac{2}{{18}} = \frac{1}{9}$                            

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

c) $\frac{4}{3} \times \frac{8}{9} = \frac{{4 \times 8}}{{3 \times 9}} = \frac{{32}}{{27}}$        

d) $\frac{5}{{12}} \times \frac{{12}}{5} = \frac{{5 \times 12}}{{12 \times 5}} = \frac{{60}}{{60}} = 1$

a) \(\dfrac{2}{3}+\dfrac{4}{9}=\dfrac{6}{9}+\dfrac{4}{9}+\dfrac{6+3}{9}=\dfrac{10}{9}\)

b)\(\dfrac{1}{10}+\dfrac{2}{5}=\dfrac{1}{10}+\dfrac{4}{10}=\dfrac{1+4}{10}=\dfrac{5}{10}=\dfrac{1}{2}\)

c) \(\dfrac{7}{22}-\dfrac{3}{11}=\dfrac{7}{22}-\dfrac{6}{22}=\dfrac{7-6}{22}=\dfrac{1}{22}\)

d) \(\dfrac{5}{6}-\dfrac{5}{12}=\dfrac{10}{12}-\dfrac{5}{12}=\dfrac{10-5}{12}=\dfrac{5}{12}\)

a)

\(\dfrac{5}{6}\times\dfrac{1}{3}\\ =\dfrac{5\times1}{6\times3}=\dfrac{5}{18}\)

b)

\(\dfrac{5}{6}:\dfrac{1}{3}=\dfrac{5}{6}\times\dfrac{3}{1}\\ =\dfrac{15}{6}\\ =\dfrac{5}{2}\)

c)

\(\dfrac{5}{3}-\dfrac{1}{3}:\dfrac{1}{4}\\ =\dfrac{5}{3}-\dfrac{1}{3}\times4\\ =\dfrac{5}{3}-\dfrac{4}{3}\\ =\dfrac{1}{3}\)

\(a,\dfrac{5}{6}x\dfrac{1}{3}=\dfrac{5}{18}\\ b,\dfrac{5}{6}:\dfrac{1}{3}=\dfrac{5}{2}\\ c,\dfrac{5}{3}-\dfrac{1}{3}:\dfrac{1}{4}=\dfrac{5}{3}-\dfrac{4}{3}=\dfrac{1}{3}\)

a) \(\dfrac{1}{2}-\dfrac{1}{6}=\dfrac{3}{6}-\dfrac{1}{6}=\dfrac{3-1}{6}=\dfrac{2}{6}=\dfrac{1}{3}\)

b) \(\dfrac{3}{4}-\dfrac{5}{8}=\dfrac{12}{8}-\dfrac{5}{8}=\dfrac{12-5}{8}=\dfrac{7}{8}\)

c) \(\dfrac{7}{10}-\dfrac{2}{5}=\dfrac{7}{10}-\dfrac{4}{10}=\dfrac{7-4}{10}=\dfrac{3}{10}\)

d) \(\dfrac{7}{12}-\dfrac{1}{3}=\dfrac{7}{12}-\dfrac{4}{12}=\dfrac{7-4}{12}=\dfrac{3}{12}=\dfrac{1}{4}\)

a) \(\dfrac{1}{3}\)
b)\(\dfrac{1}{8}\)
c)\(\dfrac{3}{10}\)
d)\(\dfrac{3}{12}\)

a) $\frac{3}{2} - \frac{1}{6} - \frac{5}{6} = \frac{9}{6} - \frac{1}{6} - \frac{5}{6} = \frac{{9 - 1 - 5}}{6} = \frac{3}{6} = \frac{1}{2}$                       

b) $1 - \frac{1}{3} - \frac{2}{3} = \frac{3}{3} - \frac{1}{3} - \frac{2}{3} = \frac{{3 - 1 - 2}}{3} = 0$

a) $\frac{1}{6} + \frac{3}{2} + \frac{1}{2} = \frac{1}{6} + \left( {\frac{3}{2} + \frac{1}{2}} \right) = \frac{1}{6} + \frac{4}{2} = \frac{1}{6} + \frac{{12}}{6} = \frac{{13}}{6}$

b) $\frac{3}{8} + \frac{1}{2} + \frac{1}{8} = \left( {\frac{3}{8} + \frac{1}{8}} \right) + \frac{1}{2} = \frac{1}{2} + \frac{1}{2} = \frac{2}{2} = 1$

c) $\frac{2}{5} + \frac{6}{{10}} + \frac{3}{5} = \frac{2}{5} + \frac{3}{5} + \frac{3}{5} = \frac{{2 + 3 + 3}}{5} = \frac{8}{5}$