280. Выполните вычитание: a) $14 - \frac{6}{9}$; б) $82 - \frac{7}{15}$; в) $5 - 4\frac{3}{4}$; г) $44 - 3\frac{8}{11}$

а) $14 - \frac{6}{9} = 13 + 1 - \frac{6}{9} = 13 + \frac{9}{9} - \frac{6}{9} = 13 + \frac{3}{9} = 13\frac{3}{9} = 13\frac{1}{3}$ б) $82 - \frac{7}{15} = 81 + 1 - \frac{7}{15} = 81 + \frac{15}{15} - \frac{7}{15} = 81 + \frac{8}{15} = 81\frac{8}{15}$ в) $5 - 4\frac{3}{4} = 5 - (4 + \frac{3}{4}) = 5 - 4 - \frac{3}{4} = 1 - \frac{3}{4} = \frac{4}{4} - \frac{3}{4} = \frac{1}{4}$ г) $44 - 3\frac{8}{11} = 44 - (3 + \frac{8}{11}) = 44 - 3 - \frac{8}{11} = 41 - \frac{8}{11} = 40 + 1 - \frac{8}{11} = 40 + \frac{11}{11} - \frac{8}{11} = 40 + \frac{3}{11} = 40\frac{3}{11}$