Répondre :
c'est une simple didributivite
F = 4×.× - 4×.1 - 7.× +7 = 4×^2 -11× + 7
F = 4×.× - 4×.1 - 7.× +7 = 4×^2 -11× + 7
F = ( x - 7 ) ( x - 1 )
= 4x * x + 4x * (-1) - 7 * x - 7 * (-1)
= 4x^2 - 4x - 7x + 7
= 4x^2 - 11x + 7
= 4x * x + 4x * (-1) - 7 * x - 7 * (-1)
= 4x^2 - 4x - 7x + 7
= 4x^2 - 11x + 7