a) 20$$\frac{3}{4}$$ - 17 = 20 - 17 - $$\frac{3}{4}$$ = 3$$\frac{3}{4}$$
Ответ: 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$$\frac{6}{11}$$
Ответ: 8$$\frac{6}{11}$$
в) 34$$\frac{7}{15}$$ - 34 = 34 - 34 + $$\frac{7}{15}$$ = $$\frac{7}{15}$$
Ответ: $$\frac{7}{15}$$
г) 29$$\frac{19}{23}$$ - 7$$\frac{6}{23}$$ = (29 - 7) + ($$\frac{19}{23}$$ - $$\frac{6}{23}$$) = 22 + $$\frac{13}{23}$$ = 22$$\frac{13}{23}$$
Ответ: 22$$\frac{13}{23}$$