Question

Aflati x, y si z daca:

$\frac{x}{3} = \frac{y}{6} ; \frac{y}{2}=z, x+2y+z=18$

RAPID VA ROG, DAU COROANA+100 PUNCTE!

Answer 1

x/3=y/6 => 6x=3y=> 2x=y
y/2=z=>2z=y=>z=x

x+2y+z=18
x+4x+x=18
6x=18
x=3=>y=6;z=3

Answer 2

$\it \dfrac{^{2)}x}{\ \ 3}=\dfrac{y}{6} \Rightarrow \dfrac{2x}{6}=\dfrac{y}{6} \Rightarrow y=2x\ \ \ \ \ (1)\\ \\ \\ \dfrac{y}{2}=z\ \stackrel{(1)}{\Longrightarrow}\ \dfrac{2x}{2}=z \Rightarrow z=x\ \ \ \ \ (2)\\ \\ \\ x+2y+z=18\ \stackrel{(1),(2)}{\Longrightarrow}\ \ x+4x+x=18 \Rightarrow 6x=18 \Rightarrow x=3\ \ \ \ \ \ (3)$

$\it (1),\ (3) \Rightarrow y=2\cdot3=6\\ \\ (2),\ (3) \Rightarrow z=x=3$