a) [tex](\frac{5}{6} + \frac{1}{3}) : (2\frac{2}{3} - 1,75)=(\frac{5}{6} +\frac{2}{6} ):(\frac{8}{3} -\frac{7}{4} )=\frac{7}{6} :(\frac{32}{12} -\frac{21}{12} )=\frac{7}{6} :\frac{1}{12} = \frac{7}{6} *\frac{2}{11} = \frac{14}{11} =1\frac{3}{11}[/tex]
b) [tex]1\frac{1}{2} :(1\frac{1}{4} :1\frac{2}{3} : 1\frac{1}5y} )=\frac{3}{2} :(\frac{5}{4} :\frac{5}{3} :\frac{6}{5} = \frac{3}{2} :(\frac{5}{4} *\frac{3}{5} *\frac{6}{5} )=\frac{3}{2} :(\frac{15}{20} :\frac{6}{5} )=\frac{3}{2} :(\frac{15}{20} *\frac{5}{6} =\frac{3}{2} :\frac{75}{120} =\frac{3}{2} *\frac{120}{75} =\frac{360}{150} =\frac{36}{15} =2,4[/tex]
