Tìm x: a) x/- 16 =- 1/6.3/4;     

a) \[\frac{x}{{ - 16}} = \frac{{ - 1}}{6}.\frac{3}{4}\]

\[\frac{x}{{ - 16}} = \frac{{ - 3}}{{24}}\]

\[x = \frac{{ - 3}}{{24}}.\left( { - 16} \right)\]

\[x = 2\]

Vậy \[x = 2\].

b) \[\frac{1}{2}x + \frac{1}{8}x = \frac{3}{4}\]

\[\left( {\frac{1}{2} + \frac{1}{8}} \right)x = \frac{3}{4}\]

\[\frac{5}{8}x = \frac{3}{4}\]

\[x = \frac{3}{4}:\frac{5}{8}\]

\[x = \frac{6}{5}\]

Vậy \[x = \frac{6}{5}\].