(2 1/4 + 3 2/3) : (8 1/2 - 1 2/5) * 1,2 = 25/36
1) 2 1/4 + 3 2/3 = 9/4 + 11/3 = 27/12 + 44/12 = 71/12 = 5 11/12,
2) 8 1/2 - 1 2/5 = 17/2 - 7/5 = 85/10 - 14/10 = 71/10 = 7 1/10,
3) 7 1/10 * 1,2 = 71/10 * 12/10 = 852/100 = 8 13/25,
4) 5 11/12 : 8 13/25 = 71/12 : 213/25 = 71/12 * 25/213 = 25/36