[tex]a) (\frac{5}{2} )^{2} =\frac{25}{4} \\b) (-\frac{4}{3} )^{3} -16=-\frac{16}{27} -16=-\frac{64}{27} -\frac{432}{27} =-\frac{496}{27} \\c)\frac{(\frac{19}{4} +\frac{13}{5}):\frac{21}{8} }{-\frac{7}{10} }=\frac{\frac{95}{20}+\frac{52}{20}*\frac{8}{21} }{-\frac{7}{10} } =\frac{\frac{147}{20}*\frac{8}{21} }{-\frac{7}{10} } =\frac{\frac{49}{270} }{-\frac{7}{10} } =\frac{49}{270} *(-\frac{10}{7}) =-\frac{7}{27}[/tex]
