Помогите номер83!!; пожалуйста

1) $(2 \frac{3}{12} +3 \frac{8}{12} ):(8 \frac{5}{10} -1 \frac{4}{10} )*1,2=5 \frac{11}{12} :7 \frac{1}{10} *1,2= \frac{71}{12} * \frac{10}{71} *1,2=$ $\frac{10}{12} * \frac{12}{10} =1$
2)( $( \frac{25}{16} * \frac{16}{5} + \frac{5}{3} -9* \frac{5}{12} ):(17 \frac{7}{12} -6 \frac{4}{12} )= (5+ \frac{5}{3} -3 \frac{3}{4} )* \frac{12}{45} = \frac{35}{12} * \frac{12}{45} = \frac{7}{9}$