[tex]Notatii: \displaystyle \\
\alpha ~~si ~~\beta ~~sunt ~unghiurile. \\ \\
Rezolvare: \\ \\
\begin{cases}
4\alpha = 6\beta \\
\alpha + \beta = 90
\end{cases} \\ \\ \\
\begin{cases}
4\alpha - 6\beta =0 \\
\alpha = 90- \beta ~~~~~(Substitutie)
\end{cases} \\ \\ \\
4(90- \beta ) -6\beta =0 \\
360 -4\beta-6\beta =0 \\
10 \beta =360 \\ \\
\beta = \frac{360}{10} = \boxed{36^o} \\ \\
\texttt{Ne intoarcem la substitutie.} \\ \\
\alpha = 90- \beta = 90 - 36 = \boxed{54^o}[/tex]
