Solutie :
[tex]\displaystyle\it\\\begin{cases}\displaystyle\it \frac{a}{b}=\frac{3}{4}\\ b-a=11 \end{Cases}\Leftrightarrow \begin{cases} \displaystyle\it \frac{a}{b}=\frac{3}{4}\\ b=11+a\end{cases}\Leftrightarrow \begin{cases} \displaystyle\it \frac{a}{11+a}=\frac{3}{4}~(1)\\ b=11+a~~~~~~~~.\end{cases}[/tex]
Rezolvam (1):
[tex]\displaystyle\it\\\frac{a}{11+a}=\frac{3}{4}\Leftrightarrow 33+3a=4a\implies\boxed{\it a=33}~~.[/tex]
Stiind a, b=11+a=11+33=44.
(a,b)∈{(33,44)}.
