Răspuns
2a/3 = 5b/6 = 8c/9 si a + b + c = 51
2a/3 = k⇒ a = 3k/2
5b/ 6 = k⇒ b = 6k/5
8c/9 = k ⇒ c = 9k/8
3k/2 + 6k/5 + 9k/8 = 51
3·4·5·k + 8·6·k + 5·9·k = 51·40
60 k + 48 k + 45 k = 2040
153 k = 2040
k = 2040 / 153
a = 3k/2= (3·2040)/(2·153) = 20
b = 6k/5=(6·2040)/(5·153) = 16
c = 9k / 8 = (9·2040)/(8·153) = 15
deci a = 20; b = 16 si c = 15
