Помогите пж( просто у меня бошка дырявая)

Решение:
$\frac{3}{4} *(- \frac{3}{5} )= -\frac{9}{20} \\- \frac{2}{7} * \frac{4}{5} = -\frac{8}{35}\\- \frac{4}{9}*(-2)= \frac{8}{9} \\\\ \frac{3}{5} *(- \frac{2}{9} ) =- \frac{6}{45} =- \frac{2}{15}\\- \frac{2}{5} * \frac{10}{21}=- \frac{20}{105}=- \frac{4}{21}\\ -\frac{3}{4} * (-\frac{8}{9})= \frac{24}{36}= \frac{6}{9}= \frac{2}{3} \\8* \frac{3}{4} *(- \frac{4}{5} )* \frac{5}{6} *(-\frac{6}{7} )* \frac{7}{8}= \frac{20160}{6720} = \frac{1008}{336}= \frac{504}{168}= \frac{x}{y} =3\\\\$ $\frac{3}{4} : (- \frac{5}{3} )= \frac{3}{4} *(- \frac{3}{5} )=- \frac{9}{20}\\- \frac{5}{3}: \frac{7}{4} =- \frac{5}{3}*\frac{4}{7} =-\frac{20}{21}\\-\frac{3}{10} :(-4)=\frac{3}{10}*\frac{1}{4} =\frac{3}{40}\\\\7:(-\frac{14}{15} ) =-7*\frac{15}{14} =- \frac{15}{2}=\frac{-75}{10}=-7.5\\-\frac{3}{8}:\frac{5}{4} =-\frac{3}{8} *\frac{4}{5} =-\frac{3}{10}=-0.3\\-\frac{22}{21} :(-\frac{2}{3} )=\frac{22}{21} *\frac{3}{2}=\frac{22}{14}= \frac{11}{7}=1 \frac{4}{7} \\$ $\frac{3}{4}:(-\frac{4}{5} ):\frac{5}{6}:(-\frac{6}{7} ) :\frac{7}{8}=\frac{3}{4}*\frac{5}{4}*\frac{6}{5}*\frac{7}{6}*\frac{8}{7}=\frac{5040}{3360}=1 \frac{5}{10}=1.5$