4.257 Вычислите: a) -4\frac{1}{3} - (-\frac{2}{9}); б) 5\frac{2}{7} - 6\frac{5}{14};

а) -4\frac{1}{3} - (-\frac{2}{9}) = -\frac{13}{3} + \frac{2}{9} = -\frac{39}{9} + \frac{2}{9} = -\frac{37}{9} = -4\frac{1}{9} б) 5\frac{2}{7} - 6\frac{5}{14} = \frac{37}{7} - \frac{89}{14} = \frac{74}{14} - \frac{89}{14} = -\frac{15}{14} = -1\frac{1}{14}