Subtraction $$ \dfrac{-5}{8} From \dfrac{-13}{16}$$Taking LCM
$$2 |8,16$$
$$2 |4,8$$
$$2 |2,4$$
$$2 |1,2$$
$$|1,1$$
∴LCM of $$8$$ and $$16=16$$
$$ \dfrac{-13}{16} - \left ( \dfrac{-5}{8} \right ) = \dfrac{-13 \times 1}{16 \times1} + \dfrac{5 \times 2}{8 \times2}$$
$$ = \dfrac{-13 + 10}{16} = \dfrac{-3}{16} $$