Татьяна7 лет назад
1) 22,2 : 5 2/7 - 2 3/5 = 222/10 : (5 * 7 + 2)/7 - (2 * 5 + 3)/5 = 222/10 : 37/7 - 13/5 = 222/10 * 7/37 - 13/5 = (222 * 7)/(10 * 37) - 13/5 = (3 * 7)/5 - 13/5 = (21 - 13)/5 = 8/5;
Ответ: 8/5.
2) (7 1/4 - 6 7/18) * 7,2 + 2,8 = ((7 * 4 + 1)/4 - (6 * 18 + 7)/18) * 72/10 + 28/10 = (29/4 - 115/18) * 36/5 + 14/5 = (9 * 29/36 - 2 * 115/36) * 36/5 + 14/5 = (261 - 230)/36 * 36/5 + 14/5 = 31/36 * 36/5 + 14/5 = 31/5 + 14/5 = (31 + 14)/5 = 45/5 = 9;
Ответ: 9.