(2 1/3-1 1/2)*2 2/5=2

2 1/3-1 1/2=2 2/6-1 3/6=5/6

5/6*2 2/5=5/6*12/5=2

4/15+4/15*3/4-1/3=-4/15

4/15*3/4=1/5

4/15-1/5=4/15-3/15=1/15

1/15-1/3=1/15-5/15=-4/15

(3 2/9-2 5/6)*(4/7+1/2)=5/12

3 2/9-2 5/6=3 4/18-2 15/18=7/18

4/7+1/2=8/14+7/14=15/14

7/18*15/14=5/12

18 1/3*1 4/11-20=5

18 1/3*1 4/11=55/3*15/11=25

25-20=5

7/12*1 1/5*24*7 1/2=126

7/12*24=14

1 1/5*7 1/2=6/5*15/2=9

14*9=126

7 6/7*6 6/11+7 6/7*5/11=7 6/7(6 6/11+5/11)=55/7*7=55