Odpowiedź:
(x-3)(x+3) - (x-3)² - (x+2)² = -25
x² - 9 - (x² - 6x +9) - (x² + 4x + 4) + 25 = 0
x² - 9 - x² + 6x - 9 - x²- 4x - 4 + 25 = 0
-x² + 2x +3 = 0
Δ = 16
[tex]\sqrt{\Delta} = 4[/tex]
[tex]x_{1} = \frac{- b - \sqrt{\Delta}}{2a} = \frac{-2-4}{-2} = 3[/tex]
[tex]x_{2} = \frac{-b+\sqrt{\Delta}}{2a} = \frac{-2+4}{-2} = - 1[/tex]
[tex]x_{1} = 3 \ \ \ \ \ V \ \ \ \ \ x_{2} = - 1[/tex]