Bonjour,
Développer :
3 - 2x(3 - x)
= 3 - 6x + 2x²
= 2x² - 6x + 3
4( x - 3) - (3 - 2x)
= 4x - 12 - 3 + 2x
= 4x + 2x - 12 - 3
= 6x - 15
(2x - 3)(5 - x) - 2(x - 3)
= 10x - 2x² - 15 + 3x - 2x + 6
= - 2x² + 10x + 3x - 2x - 15 + 6
= - 2x² + 11x - 9
4(x - 1)(2 - x)
= (4x - 4) (2 - x)
= 8x - 4x² - 8 + 4x
= - 4x² + 8x + 4x - 8
= - 4x² + 12x - 8.
