Exercice 1:
A = x(x-5) = x^2 - 5x
B = 2x(3+x) = 6x + 2x^2
C = 5x(6x-2) = 30x^2 - 10x
= 10x(3x-1)
D = (x+1)(x+2) = x^2 + 2x + x + 2
= x^2 + 3x + 2
E = (x-3)(x+5) = x^2 + 5x -3x -15
= x^2 + 2x -15
F = (x-4)(x-10) = x^2 -10x -4x +40
= x^2 -14x + 40
G = (2x+3)(3x+10) = 6x^2 + 20x + 9x +30
= 6x^2 + 29x + 30
H = (4x+1)(3x-5) = 12x^2 -20x +3x -5
= 12x^2 -17x -5
I = (6x-4)(5x-8) = 30x^2 -48x -20x +32
= 30x^2 -68x +32
Exercice 2:
pour x = 7 :
J = (7-7)(7+9)
J = 0 x 16 = 0
pour x = -9 :
J = 0
