Х) \(7\frac{4}{25} - 2\frac{3}{4}\)

\(7\frac{4}{25} - 2\frac{3}{4} = \frac{7 \times 25 + 4}{25} - \frac{2 \times 4 + 3}{4} = \frac{175 + 4}{25} - \frac{8 + 3}{4} = \frac{179}{25} - \frac{11}{4}\)

Приводим к общему знаменателю 100:

\(\frac{179}{25} = \frac{179 \times 4}{25 \times 4} = \frac{716}{100}\)

\(\frac{11}{4} = \frac{11 \times 25}{4 \times 25} = \frac{275}{100}\)

\(\frac{716}{100} - \frac{275}{100} = \frac{716-275}{100} = \frac{441}{100} = 4\frac{41}{100}\)

Ответ: \(4\frac{41}{100}\).