Выполните действия 1)(8/25*15+1/20*4)*3/5 2)(3/14+2/21)*(5/13+5/39)

Решите задачу:

$1)( \frac{8}{25} *15+ \frac{1}{20} *4)* \frac{3}{5} =( \frac{8*3}{5} + \frac{1}{5} )= \frac{24+1}{5} = \frac{25}{5} =5 \\ \\ 2)( \frac{3}{14} + \frac{2}{21} )*( \frac{5}{13} + \frac{5}{39} )=( \frac{9}{42} + \frac{4}{42} )*( \frac{15}{39} + \frac{5}{39} )=\\\\= \frac{13}{42} * \frac{75}{39} = \frac{13*75}{42*39} = \frac{1*75}{42*3} = \frac{25}{42}$