Răspuns :
a+b+c=54,c(a+b)=0,a=5b
c(a+b)=0,c=0 sau:a+b=0
Daca:c=0,a+b=54,5b+b=6b=54,b=9
a=45
Daca:a+b=0,b=54,a=0,b=0
c(a+b)=0,c=0 sau:a+b=0
Daca:c=0,a+b=54,5b+b=6b=54,b=9
a=45
Daca:a+b=0,b=54,a=0,b=0