Răspuns:
a/3=b/4=c/14=k → coeficient de proportionalitate
a=3k
b=4k
c=14k
a+b+c=42
3k+4k+14k=42
21k=42=>k=42:21=>k=2
a=3·2=6
b=4·2=8
c=14·2=28
(2a+b+c)/(b+c)=(2·6+8+28)/(8+28)=48/36=4/3
