Мария7 лет назад
(6 1/8 * 1 2/7 - 2 11/14 * 1 8/18) * 1 3/5 = 5 3/5.
1) 6 1/8 * 1 2/7 = (6 * 8 + 1)/8 * (1 * 7 + 2)/7 = (48 + 1)/8 * (7 + 2)/7 = 49/8 * 9/7 = (7 * 7 * 9)/(8 * 7) = (7 * 9)/8 = 63/8 = 7 7/8;
2) 2 11/14 * 1 8/18 = (2 * 14 + 11)/14 * (1 * 18 + 8)/8 = 39/14 * 26/8 = (39 * 2 * 13)/(2 * 7 * 8) = 507/56 = 9 3/56;
3) 7/7/8 - 9 3/56 = 7 - 3 + 7/8 - 3/56 = 4 + (7 * 7)/(7 * 8) - 3/56 = 4 + 49/56 - 3/56 = 4 52/56 = 4 26/28;
4) 4 26/28 * 1 3/5 = 98/28 * 8/5 = (98 * 4 * 2)/(4 * 7 * 5) = (98 * 2)/(7 * 5) = 196/35 = 5 21/35 = 5 3/5.