\(\begin{array}{l}a)\,\frac{3}{5} + \left( {\frac{{ - 2}}{3}} \right) - \left( {\frac{{ - 5}}{2}} \right) = \frac{3}{5} - \frac{2}{3} + \frac{5}{2}\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \,\,\frac{{ - 1}}{{15}} + \frac{5}{2}\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \,\,\frac{{73}}{{30}}\\b)\,\left( {\frac{{ - 4}}{5}} \right).\left( {\frac{{ - 15}}{2}} \right) = 2.3 = 6\\c)\,\left( { - 0,25} \right):\frac{3}{4} = \frac{{ - 1}}{4}:\frac{3}{4} = \frac{{ - 1}}{3}\\d)\,\frac{{{5^2}{{.5}^3}}}{{{5^4}}} = \frac{{{5^5}}}{{{5^4}}} = 5\end{array}\)
