B=(3/4-5/6)*3/2
B=(9/12-10/12)*3/2
B=(-1/12)*3/2
B=-3/24
B= -1/8
C= 11: (2/3-5/2)
C= 11: (4/6-15/6)
C= 11: (-11/6)
C=-6
D=3/7-15/7:5/24
D=3/7-15/7*24/5
D=3/7-3/7*24
D=3/7-72/7
D=-69/7
E=(11/7-2/5)*24/7
E=(55/35-14/35)*24/7
E=(41/35)*24/7
E= 984/245
F=25/15*(1/18+1/24)
F=25/15*(7/72)
F=35/72
