Tính:

a) $\dfrac{3}{{10}} + \left( {\dfrac{{ - 5}}{{12}}} \right)$

b) $\dfrac{{ - 3}}{8} - \left( { - \dfrac{7}{{24}}} \right)$

c) $\left( {\dfrac{{ - 5}}{{14}}} \right) + 0,25$

d) $\left( { - \dfrac{7}{8}} \right) - 1,25$

e) $\left( {\dfrac{{ - 5}}{{14}}} \right).\dfrac{{21}}{{25}}$

f) $\dfrac{8}{{27}}:\left( { - \dfrac{{16}}{{45}}} \right)$

g) $\left( {1\dfrac{5}{6}} \right):\left( {4\dfrac{1}{8}} \right)$

h) $0,38.\left( { - \dfrac{7}{{19}}} \right)$

i) $\left( {\dfrac{{ - 4}}{5}} \right).\left( {\dfrac{{15}}{{ - 8}}} \right).1\dfrac{1}{9}$