70 :
[tex] \frac{5 * 8 * 2}{2 * 3 * 5} = \frac{40 * 2}{2 * 15} = \frac{80}{30} = \frac{8}{3} [/tex]
[tex] \frac{42}{72} = \frac{7}{12} [/tex]
[tex] \frac{120}{360} = \frac{1}{3} [/tex]
71 :
[tex] \frac{3}{2} + \frac{4}{2} = \frac{7}{2} [/tex]
[tex] \frac{8}{5} - \frac{3}{4} = \frac{32}{20} - \frac{15}{20} = \frac{17}{20} [/tex]
[tex] \frac{7}{12} * \frac{4}{3} = \frac{28}{36} = \frac{7}{9} [/tex]
72 :
[tex] \frac{7}{2} - \frac{3}{4} = \frac{14}{4} - \frac{3}{4} = \frac{11}{4} [/tex]
[tex] \frac{4}{7} + 2 = \frac{8}{14} + \frac{14}{14} = \frac{22}{14} = \frac{11}{7} [/tex]
[tex] \frac{11}{4} : \frac{7}{18} = \frac{11}{4} * \frac{18}{7} = \frac{198}{28} = \frac{99}{14} [/tex]
[tex] \frac{24}{36} * \frac{9}{27} = \frac{216}{972} = \frac{2}{9} [/tex]
