Odpowiedź:
[tex](x + 1) \times (x - 2) + (x + 6) \times (x - 3) = {x}^{2} - 2x + 1x - 2 + {x}^{2} - 3x + 6x - 18 = 2 {x}^{2} + 2x - 20[/tex]
