49 ! с объяснениями! это ! 1 (12 5/12 + 1 2/3 - 3 8/6 + 2 3/4) : (2 1/2 * 2/5 - 7/9) =

(12 5/12 + 1 2/3 - 3 8/6 + 2 3/4) : (2 1/2 * 2/5 - 7/9) =

12 5/12 + 1 2/3 = 12 × 12 + 5 = 149

3 8/6 + 2 3/4 = 3 × 6 + 8 = 26

149 - 26 = 123

2 1/2 * 2/5 = 2 × 2 + 1 = 5 = 5 × 2/5 = 10/5

10/5 - 7/9 = 55/45