Bonjour,
[tex](x + 2)(x + 4) = x \times x + x \times 4 + 2 \times x + 2 \times 4 = x^2 + 4x + 2x + 8 = x^2 + 6x + 8[/tex]
[tex](-4x - 1)(-3x + 2) = -4x \times -3x -4x \times 2 - 1 \times -3x - 1 \times 2 = 12x^2 - 8x + 3x - 2 = 12x^2 - 5x - 2[/tex]
[tex](3x + 1)(-2x - 3) = 3x \times -2x + 3x \times( -3) + 1 \times -2x + 1 \times (-3) = -6x^2 - 9x - 2x - 3 = -6x^2 - 11x - 3[/tex]
Bonne journée !
