Сложите дроби предворительно сократив их 6/15 и 2/25; 1/45 и 2/36; 10/120 и 60/150; 12/360 и 20/480.
6/15 + 2/25 = 3/5 + 2/25 = 15/25 + 2/25 = 17/25 1/45 + 2/36 = 1/45 + 1/18 = 2/90 + 5/90 = 7/90 10/120 + 60/150 = 1/12 + 6/15 = 5/60 + 24/60 = 29/60 12/360 + 20/480 = 1/30 + 1/24 = 4/120 + 5/120 = 9/120 = 3/40