Ответ:

\(\frac{18}{24}=\frac{3}{4}=\frac{9}{12}\), а \(\frac{3}{8}=\frac{9}{24}\).

\(\frac{18}{24}-\frac{14}{24}+\frac{9}{24}=\frac{13}{24}\).

\(72\times\frac{13}{24}=3\times13=39\).

Ответ: \(39\)