3,75*4-2,2*(1 5/12+7/8): 11/12 решите по действиям

3,75*4-2,2*(1 5/12+7/8):11/12 = 9 1/2
1) 1 5/12 + 7/8 = 1 10/24 + 21/24 = 1 31/24 = 2 7/24
2) 3,75 * 4 = 15
3) 2,2 * 2 7/24 = 22/10 * 55/24 = 11/2 * 11/12 = 121/24 
4) 121/24 : 11/12 = 121/24 * 12/11 = 11/2 = 5 1/2
5) 15 - 5 1/2 = 14 2/2 - 5 1/2 = 9 1/2