Cest le numero 69 please !! Cest pour demain

A=(3/4-11/8):(5/3-7/4)
A=(6/8-11/8):(20/12-21/12)
A=-5/8:-1/12
A=5/8 x 12/1=60/8

B=(1/4-1/5)/(1/5-1/6)
B=(5/20-4/20)/(6/30-5/30)
B=(1/20)/(1/30)
B=1/20 x 30/1=30/20 ou 3/2

C=2/3-(-4/9+7/6)
C=2/3-(-8/18+21/18)
C=2/3-(13/18)
C=12/18-13/18=-1/18

D=(8/7-6/5)x7/4-2
D=(40/35-42/35)x7/4-2
D=-2/35x7/4-2
D=-14/140-2
D=-1/10-2
D=-1/10-20/10=-21/10