Odpowiedź :
[tex] {x}^{2} - (x + 1)(x - 2) = - 15[/tex]
[tex] {x}^{2} - ( {x}^{2} - 2x + x - 2) = - 15[/tex]
[tex] {x}^{2} - {x}^{2} + 2x - x + 2 = - 15[/tex]
[tex]2x - x = - 15 - 2[/tex]
[tex]x = - 17[/tex]
[tex] {x}^{2} - (x + 1)(x - 2) = - 15[/tex]
[tex] {x}^{2} - ( {x}^{2} - 2x + x - 2) = - 15[/tex]
[tex] {x}^{2} - {x}^{2} + 2x - x + 2 = - 15[/tex]
[tex]2x - x = - 15 - 2[/tex]
[tex]x = - 17[/tex]