Odpowiedź:
[tex](2 {x}^{2} + 4x - 3) + ( - {x}^{2} - 2x + 4) = 2 {x}^{2} + 4x - 3 - {x}^{2} - 2x + 4 = {x}^{2} + 2x + 1[/tex]