Notam numarul necunoscut cu n.
Avem :
[tex]\dfrac{n}{4}+\dfrac{n}{2}=69 \Longrightarrow \dfrac{n}{4}+\dfrac{2n}{4}=69 \Longrightarrow \dfrac{3n}{4}=69 \Longrightarrow 3n=4\cdot 69
\Longrightarrow n = \dfrac{4\cdot69}{3} \Longrightarrow n = 4\cdot 23 \Longrightarrow n = 92[/tex]
