8/9:(3/4+1/2)= 8/9:(3/4+2/4)=8/9*4/5=
= 40/45*36/45=1440/45=32
(3/5-12/25):4/5=(15/25-12/25)*5/4=3/25*5/4= 3/20
4/15:(11/5-2/3)= 4/15:(33/15-10/15)= 4/15:23/15=4/15*15/23=4/23