1) 4 1/2 - 3 5/6 = 4 3/6 - 3 5/6 = 3 9/6 - 3 5/6 = 4/6 = 2/3; 2) 2/3 * 3 1/3 = 2/3 * 10/3 = 20/9 = 2 2/9; 3) 2/7 * 3/7 = 6/49; 4) 6/49 + 2 2/9 = 54/441 + 2 98/441 = 2 152/441; 5) 6 1/2 : 9 = 13/2 : 9/1 = 13/2 * 1/9 = 13/18; 6) 2 152/441 : 13/18 = 1034/441 * 18/13 = 18612/5733 = 3 1413/5733. Ответ: 3 1413/5733.