Répondre :
C = (4/9-8/9): (16/5) = -4/9 x 5/16=-20/144=-10/72=-5/36
D=(-5/6+3/4)/(7/6-6/7)=((-20+18)/24)/(7/6-6/7)=-2/12 / ((49-36)/42)=-84/156=-42/78=-21/39=-7/13
C = (4/9-8/9): (16/5) = -4/9 x 5/16=-20/144=-10/72=-5/36
D=(-5/6+3/4)/(7/6-6/7)=((-20+18)/24)/(7/6-6/7)=-2/12 / ((49-36)/42)=-84/156=-42/78=-21/39=-7/13