a) 143 \(\frac{8}{11}\) = \(\frac{143 * 11 + 8}{11}\) = \(\frac{1573 + 8}{11}\) = \(\frac{1581}{11}\)
б) 351 \(\frac{9}{14}\) = \(\frac{351 * 14 + 9}{14}\) = \(\frac{4914 + 9}{14}\) = \(\frac{4923}{14}\)
в) 666 \(\frac{2}{7}\) = \(\frac{666 * 7 + 2}{7}\) = \(\frac{4662 + 2}{7}\) = \(\frac{4664}{7}\)
Ответ: a) \(\frac{1581}{11}\); б) \(\frac{4923}{14}\); в) \(\frac{4664}{7}\)