[tex] \frac{a}{b} = \frac{1}{2} = > \frac{a}{1} = \frac{b}{2} = k[/tex]
a=k
b=2K
[tex] \frac{c}{b} = \frac{3}{2} = > \frac{c}{3} = \frac{b}{2} = > c = 3k[/tex]
[tex] \frac{k + 4k + 3k }{2k} = \frac{8k}{2k } = \frac{8}{2} = 4[/tex]
a+c=6
4k=6
k=1,5
a=1,5
b=3
c=4,5