a,9/5-5/9=81/45-25/45 =56/45 b,7/2+4/5+3/6=105/30+24/30+15/30

=144/30=24/5

c,(5/6-4/24)+1/3=(20/24-4/24)+1/3

=2/3+1/3=1

d,(9/12-10/12)-1/8=-1/12-1/8

=-2/12-3/24

=-5/24