Помогите решить: (/-это дробь) (3 3/8∙4/9+9,54)/(5,1-2,8) 4,2/25,2 2 2/5)/(1 1/5) (4...

1) $\frac{3 \frac{3}{8}* \frac{4}{9} +9,54}{5,1-2,8} = \frac{ \frac{27}{8}* \frac{4}{9}+9,54 }{2,3} = \frac{ \frac{27*4}{8*9} +9,54}{2,3} = \frac{1,5+9,54}{2,3} = \frac{11,04}{2,3} = \frac{ \frac{1104}{100} }{ \frac{23}{10} }= \frac{1104}{100}* \frac{10}{23} = \frac{1104*100}{100*23} = \frac{48}{10} =4,8$
2) $\frac{4,2}{25,2} = \frac{ \frac{42}{10} }{ \frac{252}{10} } = \frac{42}{10} * \frac{10}{252}= \frac{42*10}{10*252} = \frac{42}{252} = \frac{1}{6}$
3) $\frac{2 \frac{2}{5} }{1 \frac{1}{5} } = \frac{12}{5}* \frac{5}{6} = \frac{12*5}{5*6} = 2$
4) $\frac{ 4\frac{2}{7}*1 \frac{3}{4} -3,36 }{0,8+1,5} = \frac{ \frac{30}{7}* \frac{7}{4} -3,36 }{2,3} = \frac{ \frac{30*7}{7*4}-3,36 }{2,3} = \frac{ \frac{30}{4} -3,36}{2,3} = \frac{7,5-3,36}{2,3} = \frac{4,14}{2,3} = \frac{ \frac{414}{100} }{ \frac{23}{10}} =\frac{414}{100} * \frac{10}{23} = \frac{414*10}{100*23} = \frac{18}{10} =1,8$
5) $- \frac{21}{8} - \frac{15}{16}=- \frac{21*2+15}{16} = -\frac{42+15}{16} = -\frac{57}{16} =-3 \frac{9}{16}$
6) $- \frac{7}{9} + \frac{5}{6} = \frac{(-7)*4+5*6}{36} = \frac{-28+30}{36}= \frac{2}{36}= \frac{1}{18}$