Answer:
[tex](a) \: - \frac{1}{2} + ( - \frac{3}{4}) \\ \\ - \frac{1}{2} - \frac{3}{4} \\ \\ - \frac{2}{4} - \frac{3}{4} \\ \\ - \frac{2 - 3}{4} = - \frac{ 5}{4} = - 1.25 = - 1 \frac{1}{4} [/tex]
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[tex](b) \: 3 \frac{1}{8} + ( - \frac{1}{4} ) \\ \\ \frac{25}{8} + ( - \frac{1}{4} ) \\ \\ \frac{25}{8} - \frac{1}{4} \\ \\ \frac{25}{8} - \frac{2}{8} \\ \\ \frac{25 - 2}{8} = \frac{23}{8} = 2.875 = 2 \frac{7}{8} [/tex]
I hope I helped you^_^
