Evaluate:

$-\dfrac{21}{16} ÷ \Big(\dfrac{-7}{8}\Big)$

$-\dfrac{21}{16} ÷ \dfrac{-7}{8}\\[1em] = -\dfrac{21}{16} \times -\dfrac{8}{7}\\[1em] = \dfrac{21 \times 8}{16 \times 7}\\[1em] = \dfrac{168}{112}\\[1em] = \dfrac{3}{2}\\[1em] = 1\dfrac{1}{2}$

Hence, $-\dfrac{21}{16} ÷ \Big(\dfrac{-7}{8}\Big) = 1\dfrac{1}{2}$