А) 13 2/5 - 11,2 : 9 1/3 = 12,2
1) 11,2 : 9 1/3 = 112/10 : 28/3 = 112/10 * 3/28 = (8*3)/(10*2) = 24/20 = 1 4/20 = 1 1/5
2) 13 2/5 - 1 1/5 = 12 1/5 = 12,2
б) 3,6 + 4,8 * (8 3/4 - 7 5/6) = 8
1) 8 3/4 - 7 5/6 = 8 9/12 - 7 10/12 = 7 21/12 - 7 10/12 = 11/12
2) 4,8 * 11/12 = 48/10 * 11/12 = 44/10 = 4,4
3) 3,6 + 4,4 = 8