Réponse :
Explications étape par étape
(a + b)^2 = a^2 + 2ab + b^2
(a - b)^2 = a^2 - 2ab + b^2
Bonsoir
Développer :
1) 7(x+5) = 7 * x + 7 * 5 = 7x + 35
2) 8(5x-3) = 8 * 5x - 8 * 3 = 40x - 24
3) -4(9x-5) = -4 * 9x - 4 * (-5) = -36x + 20
4) (x+5)(x-3) = x * x - x * 3 + 5 * x - 5 * 3 = x^2 - 3x + 5x - 15 = x^2 + 2x - 15
5) (7x+8)(6x-1) = 42x^2 - 7x + 48x - 8 = 42x^2 + 41x - 8
6) (x+7)^2 = x^2 + 14x + 49
7) (x-9)^2 = x^2 - 18x + 81
8) (4x+3)^2 = 16x^2 + 24x + 9
