Выполнить 1 2/7* 1 1/4* 4/9* 2 3/4
1 2/7* 1 1/4* 4/9* 2 3/4 =
1) 1 2/7 * 1 1/4 = 9/7 * 5/4 = 45/28
2) 45/28 *4/9 = 5/7
3) 5/7 * 2 3/4 = 5/7 * 11/4 = 55/28 = 1 27/28