Bonjour,
Factorise les expressions suivantes :
C= x²- 9 + ( x + 3 ) ( x - 9 )
C = (x - 3) (x + 3) + (x + 3) (x - 9)
C = (x + 3) (x - 3 + x - 9)
C = (x + 3) (2x - 12)
C = 2 (x - 6) (x + 3)
D= 9x² - 4 - ( 3x-2) ( 9x-4)
D = (3x - 2) (3x + 2) - (3x - 2) (9x - 4)
D = (3x - 2) [(3x + 2) - (9x - 4)]
D = (3x - 2) (3x + 2 - 9x + 4)
D = (3x - 2) (- 6x + 6)
D = x (- 6 + 1) (3x - 2)
F= (2x + 1)² -9(2x+1)
F = (2x + 1) (2x + 1) - 9 (2x + 1)
F = (2x + 1) (2x + 1 - 9)
F = (2x + 1) (2x - 8)
F = 2 (x - 4) (2x + 1)