(3 3/1+5 6/1)*5/2-2 4/3:(1 2/1-5/2)
3 3/1=6+11=17 1 2/1=3-2 1/2=2 2/2-2 1/2=1/2 17×5/2=17/1×5/2=85/2=42 1/2 2 4/3÷1/2=10/3×2/1=5/3=1 2/3 42 1/2-1 2/3=42 3/6-1 4/6=41 9/6-1 4/6=40 5/6