Sagot :
Bonsoir
1.(x+3) (x+2) = x² +2x + 3x + 6 = x² + 5x + 6
2.(x+3) (2x+4) = 2x² + 4x + 6x + 12 = 2x² + 10x + 12
3. (x-7) (x+9) = x² + 9x - 7x - 63 = x² + 2x - 63
4.(x-3) (4-x) = 4x - x² - 12 + 3x = - x² + 7x - 12.
Réponse :
Bonsoir
1.(x+3) (x+2) = x² +2x + 3x + 6 = x² + 5x + 6
2.(x+3) (2x+4) = 2x² + 4x + 6x + 12 = 2x² + 10x + 12
3. (x-7) (x+9) = x² + 9x - 7x - 63 = x² + 2x - 63
4.(x-3) (4-x) = 4x - x² - 12 + 3x = - x² + 7x - 12.
Explications étape par étape :