a)
[tex]\frac{7}{6}+(-\frac{5}{4}-\frac{4}{3})=\frac{14}{12}+(-\frac{15}{12}-\frac{16}{12})=\frac{14}{12}+(-\frac{31}{12})=\\\\\frac{14}{12}-\frac{31}{12}=-\frac{17}{12}=-1\frac{5}{12}[/tex]
b)
[tex]-1\frac{9}{16}+\frac{11}{12}=-\frac{25}{16}+\frac{11}{12}=-\frac{75}{48}+\frac{44}{48}=-\frac{31}{48}[/tex]
c)
[tex]\frac{1}{2}-\frac{1}{3}-(\frac{1}{4}-\frac{1}{5})=\frac{1}{2}-\frac{1}{3}-(\frac{5}{20}-\frac{4}{20})=\frac{1}{2}-\frac{1}{3}-(\frac{1}{20})=\\\\\frac{1}{2}-\frac{1}{3}-\frac{1}{20}=\frac{30}{60}-\frac{20}{60}-\frac{3}{60}=\frac{7}{60}[/tex]
d)
[tex]-(-2\frac{2}{3})+\frac{7}{15}=2\frac{2}{3}+\frac{7}{15}=\frac{8}{3}+\frac{7}{15}=\frac{40}{15}+\frac{7}{15}=\frac{47}{15}=3\frac{2}{15}[/tex]
