Вправи 1001 - 1100 » 1075

Зведіть подібні доданки: 1) 3/7a – 2/15b – 5/14a + 7/30b = (3/7 – 5/14)a + (7/30 – 2/15)b = (6/14 – 5/14)a + (7/30 – 4/30)b = 1/14a + 3/30b = 1/14a + 1/10b; 2) 7/18b – 13/28c – 15/14c – 23/36b + 4/7c + 4/9b = (7/18 – 23/36 + 4/9)b – (13/28 + 5/14 – 4/7)c = (14/36 – 23/36 + 16/36)b – (13/28 + 10/28 – 16/28)c = 7/36b – 7/28c = 7/36b – 1/4c.