Tìm x , biết: k) 3/4 : x − 1/3 = 5/14 ⋅ − 7/6 .

k) \(\frac{3}{4}:x - \frac{1}{3} = \frac{5}{{14}} \cdot \frac{{ - 7}}{6}\)

\(\frac{3}{4}:x - \frac{1}{3} = \frac{{5 \cdot \left( { - 7} \right)}}{{14 \cdot 6}}\)

\(\frac{3}{4}:x - \frac{1}{3} = \frac{{ - 5}}{{12}}\)

\(\frac{3}{4}:x = \frac{{ - 5}}{{12}} + \frac{1}{3}\)

\(\frac{3}{4}:x = \frac{{ - 5}}{{12}} + \frac{4}{{12}}\)

\(\frac{3}{4}:x = \frac{{ - 1}}{{12}}\)

\(x = \frac{3}{4}:\frac{{ - 1}}{{12}}\)

\(x = \frac{3}{4} \cdot \left( { - 12} \right)\)

\(x =  - 9.\)

Vậy \(x =  - 9.\)