Tính giá trị của các biểu thức sau (tính hợp lí nếu có thể):

a) \(\frac{7}{4} - \frac{3}{4}:\frac{{ - 1}}{3} = \frac{7}{4} - \frac{3}{4}.\frac{3}{{ - 1}} = \frac{7}{4} + \frac{9}{4} = 4\);

b) \[\left( {{{15}^5}:{5^5}} \right).\left( {{3^5}:{6^5}} \right) = {\left( {15:3} \right)^5}.{\left( {3:6} \right)^5} = {5^5}:{\left( {\frac{1}{2}} \right)^5} = {\left( {5:\frac{1}{2}} \right)^5} = {10^5} = 100\,\,000\];

c) \(\sqrt {\frac{{49}}{{81}}} - \left| {\frac{{ - 7}}{3}} \right| = \frac{7}{9} - \frac{7}{3} = \frac{{21}}{{27}} - \frac{{63}}{{27}} = \frac{{ - 42}}{{27}} = - \frac{{14}}{9}\);

d) \(\frac{1}{9}.\frac{2}{7} + \frac{1}{9}:\frac{7}{5} + \frac{{{{\left( { - 1} \right)}^0}}}{7} = \frac{1}{9}.\frac{2}{7} + \frac{1}{9}.\frac{5}{7} + \frac{1}{7} = \frac{1}{9}.\left( {\frac{2}{7} + \frac{5}{7}} \right) + \frac{1}{7} = \frac{1}{9}.1 + \frac{1}{7} = \frac{7}{{63}} + \frac{9}{{63}} = \frac{{16}}{{63}}\).