A= 15 + 10/5 = (15 X 5)/5 + 10/5 = 75/5 + 10/5 = 85/5 = 17
B= 12.2 - 2.2 X 5 = 12.2 - 11 = 1.2
C= 9.9/3 - 3.1 = (3 X 3.3)/3 - 3.1 = 3.3 - 3.1 = 0.2
D= 9.2 - 7.2/9 = 82.8/9 - 7.2/9 = 75.6/9 = 8.4
E= 1 + 9 X 3.4 = 1 + 9 X 3 + 9 X 0.4 = 1 + 27 + 3.6 = 31.6
F= 0.9/6 +2.1 = 0.9/6 + 12.6/6 = 13.5/6 = 2.25