Bonjour , Factoriser si possible les expressions suivantes en detaillant les calculs.
a) 7x -21
b) 36x²-24x
c) 4x (x+3) + (x+3)(3x-11)
d) (3x -1)² - 25 + (3x+4) (x-9)
e) (9x²+6x + 1) - 12x-4
f) 81 + 625 x²
G) x² -20x +81
Cordialement
Julien
A = 7x - 21
A = 7(x - 3)
B = 36x² - 24x
B = x(36x - 24)
C = 4x(x+3) + (x+3)(3x-11)
C = (x + 3)(4x + 3x - 11)
C = (x + 3)(7x - 11)
D = (3x - 1)² - 25 + (3x+4)(x-9)
D = (3x - 1 - 5)(3x - 1 + 5) + (3x + 4)(x - 9)
D = (3x - 6)(3x + 4) + (3x + 4)(x - 9)
D = (3x + 4)(3x - 6 + x - 9)
D = (3x + 4)(4x - 15)
E = (9x² + 6x + 1) - 12x - 4
E = 9x² + 6x + 1 - 12x - 4
E = 9x² - 6x - 3
E = 3(3x² - 2x)