Chapter 1-2 - Cumulative Review - Page 152: 4

$10$

To divide fractions, multiply the dividend by the reciprocal of the divisor. The quotient is positive if the dividend and divisor have the same signs. Otherwise, the quotient is negative. Hence, \begin{array}{l}\require{cancel} -5\div\left(-\dfrac{1}{2} \right) \\\\= 5\div\dfrac{1}{2} \\\\= 5\cdot\dfrac{2}{1} \\\\= 5\cdot2 \\\\= 10 .\end{array}