FRAC{s(s-c)}{ab}+c\frac{s(s-a)}{bc}=\frac{3b}{
2
}\] Þ \[
2S
(s-c+s-a)=3{{b}^{2}}\] Þ \[2s(b)=3{{b}^{2}}\Rightarrow 2s=3b\] Þ \[a+b+c=3b\Rightarrow a+c=2b\Rightarrow a,b,c\]are in A.P.