a, 23/4 : 3 + 9/4 x 1/3 - 3/8
= 7,8 + 12,22 - 3,8
= 20,02 - 3,8
=16,22
b, 3/5 : 5/6 : 6/7 : 7/8 + 2/5 +23/35
=3/5 x 6/5 x 7/6 x 8/7 + 2/5 + 23/35
=24/25 + 2/5 + 23/35
=1/5 x(24/5 + 2 +23/7)
=1/5 x 353/35
=353/175
a, 23/4 : 3 + 9/4 x 1/3 - 3/8= 7,8 + 12,22 - 3,8= 20,02 - 3,8 =16,22b, 3/5 : 5/6 : 6/7 : 7/8 + 2/5 +23/35 =3/5 x 6/5 x 7/6 x 8/7 + 2/5 + 23/35=24/25 + 2/5 + 23/35=1/5 x(24/5 + 2 +23/7)=1/5 x 353/35=353/175