Задание 3. Вычислите: 57/68 − 38/136; 21/36 − 3/13; 67/82 − 6/34; 9/12 − 2/4; 16/25 − 4/5; 17/32 − 3/16.

1. \(\frac{57}{68}-\frac{38}{136}=\frac{57}{68}-\frac{19}{68}=\frac{38}{68}=\frac{19}{34}\).
2. \(\frac{21}{36}-\frac{3}{13}=\frac{7}{12}-\frac{3}{13}=\frac{91}{156}-\frac{36}{156}=\frac{55}{156}\).
3. \(\frac{67}{82}-\frac{6}{34}=\frac{67}{82}-\frac{3}{17}=\frac{1139}{1394}-\frac{246}{1394}=\frac{893}{1394}\).
4. \(\frac{9}{12}-\frac{2}{4}=\frac{3}{4}-\frac{1}{2}=\frac{1}{4}\).
5. \(\frac{16}{25}-\frac{4}{5}=\frac{16}{25}-\frac{20}{25}=-\frac{4}{25}\).
6. \(\frac{17}{32}-\frac{3}{16}=\frac{17}{32}-\frac{6}{32}=\frac{11}{32}\).

Ответ: \(\frac{19}{34};\ \frac{55}{156};\ \frac{893}{1394};\ \frac{1}{4};\ -\frac{4}{25};\ \frac{11}{32}\).