a) \[20\frac{3}{4} - 17 = (20 - 17) + \frac{3}{4} = 3 + \frac{3}{4} = 3\frac{3}{4}\]
б) \[13\frac{8}{11} - 5\frac{2}{11} = (13 - 5) + (\frac{8}{11} - \frac{2}{11}) = 8 + \frac{8-2}{11} = 8 + \frac{6}{11} = 8\frac{6}{11}\]
в) \[34\frac{7}{15} - 34 = \frac{34 \cdot 15 + 7}{15} - 34 = \frac{510 + 7}{15} - 34 = \frac{517}{15} - 34 = 34\frac{7}{15} - 34 = \frac{7}{15}\]
г) \[29\frac{19}{23} - 23 = (29 - 23) + \frac{19}{23} = 6 + \frac{19}{23} = 6\frac{19}{23}\]
Ответ:
a) \[3\frac{3}{4}\];
б) \[8\frac{6}{11}\];
в) \[\frac{7}{15}\];
г) \[6\frac{19}{23}\]