Answer:
[tex] \frac{3}{4} + \frac{7}{10} - \frac{1}{8} ( - \frac{1}{2} ) \\ taking \: l.c.m \: of \: 4.10and8 = 40 \\ \frac{30}{40} + \frac{24}{40} - \frac{5}{40} ( - \frac{1}{2} ) \\ \frac{30 + 24 - 5}{40} ( - \frac{1}{2}) \\ \frac{49}{40}( - \frac{1}{2} ) \\ 1.225( - 0.5) \\ - 0.125 \: \: \: answer[/tex]