Răspuns:
a/2=b/3=c/5=k
a=2k
b=3k
c=5k
(2k-3k)^2 + (3k-5k)^2 + (5k-2k)^2 = 126
k^2 + 4k^2 + 9k^2 = 126
14k^2 = 126
k^2 = 9 =>k=3 sau -3
Dar a, b, c € N =>k=3
a=6
b=9
c=15