Răspuns:
[tex]\frac{a}{2}= \frac{b}{3} = \frac{c}{4} = k\\\\\frac{a}{2} = k =>a = 2k\\\frac{b}{3} = k =>b = 3k\\\frac{c}{4} = k =>c = 4k[/tex]
[tex]2k * 3k * 4 k = 648\\\\k^{3} = 27 => k^{3} = 3^{3} => k = 3[/tex]
[tex]a = 2 * 3 => a = 6\\\\b = 3 * 3 => b = 9\\\\c = 3*4 => c = 12[/tex]
Verificare: 6 * 9 * 12 = 648