a) 20 3/4 – 17 = 20 - 17 + 3/4 = 3 + 3/4 = 3 3/4
Ответ: $$3 \frac{3}{4}$$
б) 13 8/11 – 5 2/11 = (13 - 5) + (8/11 - 2/11) = 8 + 6/11 = 8 6/11
Ответ: $$8 \frac{6}{11}$$
в) 34 7/15 – 34 = 34 - 34 + 7/15 = 0 + 7/15 = 7/15
Ответ: $$\frac{7}{15}$$
г) 29 19/23 - 7 6/23 = (29 - 7) + (19/23 - 6/23) = 22 + 13/23 = 22 13/23
Ответ: $$22 \frac{13}{23}$$