Евгения7 лет назад
1) 2/17 + 7/17 = (2 + 7)/17 = 9/17;
2) 7/16 - 5/16 = (7 - 5)/16 = 2/16 = 2/(2 * 8) = 1/8;
3) 2/25 + 9/25 = (2 + 9)/25 = 11/25;
4) 12/13 - 3/13 = (12 - 3)/13 = 9/13.
Решим подобные примеры, для закрепления материала:
1) 3/14 + 5/14 = (3 + 5)/14 = 8/14 = (2 * 4)/(2 * 7) = 4/7;
2) 5/18 + 5/18 = (5 + 5)/18 = 10/18 = (2 * 5)/(2 * 9) = 5/9;
3) 7/10 + 3/10 = (7 + 3)/10 = 10/10 = 1;
4) 9/22 + 3/22 = (9 + 3)/22 = 12/22 = (2 * 6)/(2 * 11) = 6/11;
5) 3/26 + 7/26 + 5/26 = (3 + 7)/26 + 5/26 = 10/26 + 5/26 = (10 + 5)/26 = 15/26.