bjr
3x² - 5x² + 8x = 3x*x - 5x*x + 8x
= 3x*x - 5x*x + 8x
= x(3x - 5x + 8)
= x(-2x + 8) on peut mettre 2 en facteur
= x*2(-x + 4)
= 2x(-x + 4)
(2x - 3)(24x - 3)+(2x - 3)(-22x + 5) =
(2x - 3) (24x - 3 -22x + 5) =
(2x - 3)(2x + 2) = on peut mettre 2 en facteur
(2x - 3)*2*(x + 1) =
2(2x - 3)(x + 1)
(15x + 7)(3 - x)+(12x + 5)(15x + 7) =
(15x + 7)(3 - x+ 12x + 5) =
(15x + 7)(11x + 8)
(13t + 5)(-5t + 2) - (8t - 15)(13t + 5) =
(13t + 5)[(-5t + 2) - (8t - 15)] =
(13t + 5)(-5t + 2 - 8t + 15) =
(13t + 5)(-13t + 17)