$$\left. \begin{array} { l } { 1 f ( x + 1 ) = 11 x 1 = 25 x f } \\ { a ^ { 2 } - 2 y + y ^ { 2 } = 8 y } \end{array} \right.$$
$\left\{\begin{matrix}x=\frac{11x_{1}}{f}-1\text{, }&f\neq 0\\x\in \mathrm{C}\text{, }&x_{1}=0\text{ and }f=0\end{matrix}\right.$
$\left\{\begin{matrix}x=\frac{11x_{1}}{f}-1\text{, }&f\neq 0\\x\in \mathrm{R}\text{, }&x_{1}=0\text{ and }f=0\end{matrix}\right.$
