Выполните действия: a) $$12\frac{43}{56} - 4\frac{22}{56}$$; б) $$\frac{25}{34} - \frac{8}{34}$$

a) $$12\frac{43}{56} - 4\frac{22}{56} = (12-4) + (\frac{43}{56} - \frac{22}{56}) = 8 + \frac{43-22}{56} = 8 + \frac{21}{56} = 8 + \frac{21:7}{56:7} = 8 + \frac{3}{8} = 8\frac{3}{8}$$

б) $$\frac{25}{34} - \frac{8}{34} = \frac{25-8}{34} = \frac{17}{34} = \frac{17:17}{34:17} = \frac{1}{2}$$

Ответ: a) $$8\frac{3}{8}$$; б) $$\frac{1}{2}$$