5.279 Найдите разность: a) 20$$\frac{3}{4}$$ - 17; б) 13$$\frac{8}{11}$$ - 5$$\frac{2}{11}$$; г) 29$$\frac{19}{23}$$ - 7$$\frac{6}{23}$$

a) $$20\frac{3}{4} - 17 = (20 - 17) + \frac{3}{4} = 3 + \frac{3}{4} = 3\frac{3}{4}$$ б) $$13\frac{8}{11} - 5\frac{2}{11} = (13 - 5) + (\frac{8}{11} - \frac{2}{11}) = 8 + \frac{6}{11} = 8\frac{6}{11}$$ г) $$29\frac{19}{23} - 7\frac{6}{23} = (29 - 7) + (\frac{19}{23} - \frac{6}{23}) = 22 + \frac{13}{23} = 22\frac{13}{23}$$