461. 5 1/5 + x : 3 1/3 = 5 1/4 + 4 1/2.

\(\frac{x}{3\frac{1}{3}}=5\frac{1}{4}+4\frac{1}{2}-5\frac{1}{5}=\frac{91}{20}\).

Тогда \(x=\frac{91}{20}\cdot\frac{10}{3}=\frac{91}{6}\).

Ответ: \(x=15\frac{1}{6}\).