Question

-1/2 + [ 3/7 + ( -3/4 )]​

Answer 1

$- \frac{1}{2} + [ \frac{3}{7} + ( - \frac{3}{4} ) ] \\ - \frac{1}{2} + \frac{3}{7} - \frac{3}{4} \\ \frac{ - 1 \times 14 + 3 \times 4 - 3 \times 4}{28} \\ \frac{ - 14 + 12 - 12}{28} \\ \cancel \frac{ - 14}{28} = - \frac{ 1}{2}$