y) \(\left(4 \frac{3}{4}\right)^2\)

\( \left(4 \frac{3}{4}\right)^2 = \left(\frac{4 \cdot 4 + 3}{4}\right)^2 = \left(\frac{16+3}{4}\right)^2 = \left(\frac{19}{4}\right)^2 = \frac{19^2}{4^2} = \frac{361}{16} \)

\( \frac{361}{16} = 22 \frac{9}{16} \)

Ответ: \(22 \frac{9}{16}\).