Answer:
[tex]A) - \frac{1}{4} + \frac{2}{3} \\ \frac{ - 3 + 8}{12} \\ = \frac{5}{12} [/tex]
[tex]B) \frac{1}{2} - \frac{3}{5} - \frac{1}{2} \\ \frac{5 - 6 - 5}{10} \\ = \frac{ - 6}{10} [/tex]
[tex]C) \frac{3}{4} of \frac{2}{9} \\ \frac{3}{4} \times \frac{2}{9} \\ \frac{6}{36} = \frac{1}{6} [/tex]
[tex]D) \frac{2}{5} \times \frac{7}{12} \\ = \frac{14}{60} = \frac{7}{30} [/tex]