(3 1/4+2 1/6) :2 3/5 -2/3:4/9

Пошаговое объяснение:

(3 1/4+2 1/6) :2 3/5 -2/3 : 4/9 = 7/12

1) 3 1/4+2 1/6 = 3 3/12 + 2 2/12 = 5 5/12

2) 5 5/12 : 2 3/5 = 65/12 : 13/5 = 65/12 * 5/13 = 25/12 = 2 1/12

3) 2/3 : 4/9 = 2/3 * 9/4 = 3/2 = 1 1/2

4) 2 1/12 - 1 1/2 = 2 1/12 - 1 6/12 = 1 13/12 - 1 6/12 = 7/12