3. d) [latex]frac{7}{6}+left(- frac{5}{4}- frac{4}{3} ight)=frac{14}{12}+left(- frac{15}{12}- frac{16}{12} ight)=[/latex] [latex]frac{14}{12}+left(- frac{31}{12} ight)=frac{14}{12}- frac{31}{12}=- frac{17}{12}=-1 frac{5}{12}[/latex] ------------------ e) [latex]-left(-2 frac{2}{3} ight)+ frac{7}{15}=2 frac{10}{15}+ frac{7}{15}=2 frac{17}{15}=3 frac{2}{15}[/latex] ------------------ f) [latex]-1 frac{9}{16}+ frac{11}{12}=-1 frac{27}{48}+ frac{44}{48}=-frac{75}{48}+ frac{44}{48}=- frac{31}{48}[/latex] ================== 4. a) [latex]-2 frac{1}{3}cdot left(- frac{27}{28} ight)=-frac{7}{3}cdot left(- frac{27}{28} ight)= frac{9}{4}=2 frac{1}{4}[/latex] ================== 5. d) [latex]frac{2- frac{1}{3} }{2- frac{1}{2} } =frac{1frac{2}{3} }{1 frac{1}{2} } = frac{frac{5}{3} }{frac{3}{2} }= frac{5}{3}:frac{3}{2}=frac{5}{3}cdot frac{2}{3}= frac{10}{9}=1 frac{1}{9}[/latex] ------------------ e) [latex]frac{frac{3}{4}+ frac{1}{8} }{frac{3}{4}- frac{1}{8} }=frac{frac{6}{8}+ frac{1}{8} }{frac{6}{8}- frac{1}{8} }=frac{frac{7}{8}}{frac{5}{8}}= frac{7}{8}:frac{5}{8}=frac{7}{8}cdot frac{8}{5}= frac{7}{5}=1 frac{2}{5}[/latex] ------------------ f) [latex]frac{frac{1}{2}-1 frac{2}{5} }{frac{1}{2}-1 frac{1}{5} }=frac{frac{5}{10}-1 frac{4}{10} }{frac{5}{10}-1 frac{2}{10} }=frac{frac{5}{10}-frac{14}{10} }{frac{5}{10}-frac{12}{10} }=frac{-frac{9}{10} }{-frac{7}{10} }=[/latex] [latex]-frac{9}{10}:left(-frac{7}{10} ight)=-frac{9}{10}cdot left(-frac{10}{7} ight)= frac{9}{7}=1 frac{2}{7}[/latex]
