Exercitiul 10 prima ecuatie,va rog

a/4=b/6 => b=3a/2
a/4=c/8 => c=2a
inlocuiesti in a doua si ai ca:
1/a+1/(3a/2)+1/(2a)=13/144
Dai 1/a factor comun
1/a(1+2/3+1/2)=13/144
1/a(13/6)=13/144
1/a=13/144:13/6
1/a=1/24
a=24
b=36
c=48