[tex] \frac{x + y + z}{3} = 6[/tex]
[tex]z = \frac{x + y}{4} [/tex]
inlocuim
[tex] \frac{x + y + \frac{x + y}{4} }{3} = 6[/tex]
si inmultind
[tex]x + y + \frac{x + y}{4} = 18[/tex]
[tex] \frac{4x+ 4y + x + y}{4} = 18[/tex]
[tex]5 x + 5y = 72[/tex]
[tex]5(x + y) = 72[/tex]
[tex]x + y = \frac{72}{5} = 14.4[/tex]
[tex]z = \frac{x + y}{4} = \frac{14.4}{4} = 3.6[/tex]