Помогите пожалуйста решить даю 20 балов номер 51

Question 1

Помогите пожалуйста решить даю 20 балов
номер 51

Question 2

1)
$12:3 \frac{3}{8} -1 \frac{1}{4} : \frac{15}{32} =12:\frac{26}{8} -\frac{5}{4} : \frac{15}{32} =12*\frac{8}{26} -\frac{5}{4}*\frac{32}{15} = \\ =6*\frac{8}{13} -\frac{1}{4}*\frac{32}{3} =\frac{48}{13} -\frac{1}{1}*\frac{8}{3} =3 \frac{9}{13} -2\frac{2}{3} =3 \frac{27}{39} -2\frac{6}{39} =1 \frac{21}{39}$

2)
$1 \frac{31}{35}:(2- \frac{8}{9}:1 \frac{19}{45} ) =\frac{66}{35}:(2- \frac{8}{9}:\frac{64}{45} ) =\frac{66}{35}:(2- \frac{8}{9}*\frac{45}{64} ) = \\ =\frac{66}{35}:(2- \frac{1}{1}*\frac{5}{8} ) = \frac{66}{35}:(2- \frac{5}{8} ) = \frac{66}{35}:\frac{3}{8} = 66/35*8/3=22/35*8= \\ =176/35=5 \frac{1}{35}$

3)
$(1 \frac{1}{35}: \frac{4}{5}-1 \frac{8}{35} )*3 \frac{1}{3} =(\frac{36}{35}*\frac{5}{4}-1 \frac{8}{35} )*\frac{10}{3} =(\frac{9}{35}*\frac{5}{1}-1 \frac{8}{35} )*\frac{10}{3} = \\ =(\frac{45}{35}-1 \frac{8}{35} )*\frac{10}{3} = (1\frac{10}{35}-1 \frac{8}{35} )*\frac{10}{3} = \frac{2}{35}*\frac{10}{3} = \frac{2}{7}*\frac{2}{3} =4/21$

4)
$(7-1 \frac{5}{9}: \frac{7}{24} ): \frac{20}{27} =(7-\frac{14}{9}: \frac{7}{24} )* \frac{27}{20} =(7-\frac{14}{9}* \frac{24}{7} )* \frac{27}{20} = \\ =(7-\frac{2}{3}* \frac{8}{1} )* \frac{27}{20} =(7-\frac{16}{3})* \frac{27}{20} =(7-5\frac{1}{3})* \frac{27}{20} =1\frac{2}{3}* \frac{27}{20} = \\ =\frac{5}{3}* \frac{27}{20} =\frac{1}{1}* \frac{9}{4} =9/4=2 \frac{1}{4}=2.25$