[tex]e) \frac{1}{21} - 1 \times \frac{4}{7} - \frac{2}{ - 3} [/tex]
[tex] \frac{1}{21} - \frac{11}{7} - \frac{2}{ - 3} [/tex]
[tex] = - \frac{6}{7} [/tex]
[tex]c) - \frac{5}{6} - ( \frac{1}{2} - \frac{1}{3} ) [/tex]
[tex] - \frac{5}{6} - \frac{1}{6} [/tex]
[tex] = - 1[/tex]
