Thực hiện phép tính

f) \(\frac{{\sqrt {{3^2}} + \sqrt {{{39}^2}} }}{{\sqrt {{{91}^2}} - \sqrt {{{( - 7)}^2}} }}\);

d) \({\left( {\frac{1}{3}} \right)^{50}} \cdot {\left( { - 9} \right)^{25}} - \frac{2}{3}:4\)

\( = {\left[ {{{\left( {\frac{1}{3}} \right)}^2}} \right]^{25}} \cdot {\left( { - 9} \right)^{25}} - \frac{2}{3}:4\)

\( = {\left( {\frac{1}{9}} \right)^{25}} \cdot {\left( { - 9} \right)^{25}} - \frac{2}{3}:4\)

\( = \left[ {\frac{1}{{{9^{25}}}}.{{\left( { - 9} \right)}^{25}}} \right] - \frac{2}{3}:4\)

\( = {\left( {\frac{{ - 9}}{9}} \right)^{25}} - \frac{2}{3}.\frac{1}{4}\)

k) \({\left( {\frac{3}{5}} \right)^{10}}.{\left( {\frac{5}{3}} \right)^{10}} - \frac{{{{13}^4}}}{{{{39}^4}}} + {2014^0}\)

\( = {\left( {\frac{3}{5}.\frac{5}{3}} \right)^{10}} - {\left( {\frac{{13}}{{39}}} \right)^4} + 1\)

\( = 1 - {\left( {\frac{1}{3}} \right)^4} + 1\)