(x-3)(x+5) + x2 - 9 = 0
(x-3)(x+5) +(x-3)(x+3) = 0
( x-3) ( x+5 + x+3) = 0
(x-3)( 2x+8) =0
\(\left[{}\begin{matrix}x-3=0\\2x+8=0\end{matrix}\right.\)
\(\left[{}\begin{matrix}x=3\\2x=-8\end{matrix}\right.\)
\(\left[{}\begin{matrix}x=3\\x=-4\end{matrix}\right.\)
Kl: \(x\in\) { -4; 3}