13. Вычислите: $$\frac{8}{15} + (2 - 1\frac{13}{28}) : \frac{25}{49} - 1\frac{1}{4}$$

$$\frac{8}{15} + (2 - 1\frac{13}{28}) : \frac{25}{49} - 1\frac{1}{4} = $$ $$\frac{8}{15} + (2 - \frac{41}{28}) : \frac{25}{49} - \frac{5}{4} = $$ $$\frac{8}{15} + (\frac{56}{28} - \frac{41}{28}) : \frac{25}{49} - \frac{5}{4} = $$ $$\frac{8}{15} + \frac{15}{28} : \frac{25}{49} - \frac{5}{4} = $$ $$\frac{8}{15} + \frac{15}{28} \cdot \frac{49}{25} - \frac{5}{4} = $$ $$\frac{8}{15} + \frac{3}{4} \cdot \frac{7}{5} - \frac{5}{4} = $$ $$\frac{8}{15} + \frac{21}{20} - \frac{5}{4} = $$ $$\frac{32}{60} + \frac{63}{60} - \frac{75}{60} = $$ $$\frac{95}{60} - \frac{75}{60} = $$ $$\frac{20}{60} = \frac{1}{3}$$ Ответ: **$$\frac{1}{3}$$**