[tex]( \frac{5}{6} + \frac{11}{9} ): \frac{74}{9} = \frac{3*5+2*11}{18} * \frac{9}{74} = \frac{37}{18}* \frac{9}{74}= \frac{1}{4} [/tex]
[tex]( \frac{11}{6} + \frac{3}{4} ): \frac{31}{24} = \frac{2*11+3*3}{12} * \frac{24}{31} = \frac{31}{12}* \frac{24}{31}= 2[/tex]
[tex]( \frac{1}{6} + \frac{17}{8} ): \frac{77}{24} + \frac{2}{7} = \frac{4*1+3*17}{24} * \frac{24}{77}+ \frac{2}{7}= \frac{55}{24}* \frac{24}{77}+\frac{2}{7}= \frac{5}{7}+\frac{2}{7}=\frac{7}{7}=1[/tex]
[tex]( \frac{11}{12} - \frac{13}{18} ): 7 = \frac{3*11-2*13}{36} * \frac{1}{7} = \frac{7}{36}* \frac{1}{7}= \frac{1}{36} [/tex]
[tex]( \frac{19}{45} - \frac{7}{30} ): \frac{34}{5}= \frac{2*19-3*7}{36} * \frac{5}{34} = \frac{17}{90}* \frac{5}{34}= \frac{1}{36} [/tex]
[tex]( \frac{13}{12} - \frac{7}{15} ): \frac{37}{30}+ \frac{1}{2} = \frac{5*13-4*7}{60} * \frac{30}{37}+ \frac{1}{2} = \frac{37}{60}* \frac{30}{37}+ \frac{1}{2} = \frac{1}{2}+ \frac{1}{2} = \frac{2}{2} =1[/tex]
[tex]( \frac{12}{25} :\frac{4}{5} ): \frac{9}{35} = (\frac{12}{25} * \frac{5}{4} )*\frac{35}{9}= \frac{3}{5}* \frac{35}{9}= \frac{7}{3} [/tex]
[tex]\frac{12}{15} :(\frac{4}{5} : \frac{9}{33} )= \frac{12}{15}:(\frac{4}{5} *\frac{9}{33})= \frac{12}{15}:\frac{12}{55}= \frac{12}{15}*\frac{55}{12}=\frac{11}{3}[/tex]
[tex]( \frac{25}{36} :\frac{7}{16} ): (\frac{60}{49}: \frac{162}{7} )= (\frac{25}{36} * \frac{16}{7} ):(\frac{60}{49}*\frac{7}{162})=\frac{100}{63} :\frac{10}{189}=\frac{100}{63} *\frac{189}{10}=30[/tex]
[tex]( \frac{11}{12} :\frac{13}{18} ): \frac{22}{33}= (\frac{11}{12} * \frac{18}{13} )*\frac{33}{22}=\frac{33}{26}*\frac{3}{2}=\frac{99}{54} [/tex]
[tex]( \frac{19}{45} -\frac{7}{30} ): \frac{19}{21} = \frac{2*19-3*7}{90} * \frac{21}{19} =\frac{17}{90} * \frac{21}{19}=\frac{119}{570} [/tex]
[tex]( \frac{13}{12}:\frac{7}{15} ): \frac{39}{70} = (\frac{13}{12} * \frac{15}{7}) *\frac{70}{39}=\frac{65}{28} * \frac{70}{39}=\frac{325}{78} [/tex]
