Răspuns :
(x + 4)(x - 3) - (x - 1)(x + 6) =
x² - 3x + 4x - 12 - (x² + 6x - x - 6) =
x² + x - 12 - x² - 5x + 6 =
- 4x - 6 =
- (4x + 6)
x² - 3x + 4x - 12 - (x² + 6x - x - 6) =
x² + x - 12 - x² - 5x + 6 =
- 4x - 6 =
- (4x + 6)