Répondre :
a) F = (3x-5)²-(3x-5)(x+4)
F = 9x²-30x+25-(3x²+12x-5x-20)
F = 6x²-37x+45
b) F = (3x-5)²-(3x-5)(x+4)
F = (3x-5)[(3x-5)-(x+4)]
F = (3x-5)(2x-9)
c) F = (3x-5)(2x-9)
F = (3-5)*(2-9)
F = 14
F = (3x-5)(2x-9)
F = (13,5-5)(9-9)
F = 0
F = 9x²-30x+25-(3x²+12x-5x-20)
F = 6x²-37x+45
b) F = (3x-5)²-(3x-5)(x+4)
F = (3x-5)[(3x-5)-(x+4)]
F = (3x-5)(2x-9)
c) F = (3x-5)(2x-9)
F = (3-5)*(2-9)
F = 14
F = (3x-5)(2x-9)
F = (13,5-5)(9-9)
F = 0