Exercice 1 :
A= 7(1-2y)
A = 7×1 + 7× - 2y
A = 7 - 14y
B= (x-2)(x+1)
B = x×x + x×1 - 2×x - 2×1
B = x² + x - 2x - 2
B = x² - x - 2
L= (5-2x)(1+3x)-2x(7-4x)
L = 5×1 + 5×3x - 2x×7 - 2x × - 4x
L = 5 + 15x - 2x -6x² - 14x + 8x²
L = 2x² - x + 5
M= 11x - (2x+1)(7x-6)
M = 11x - [ 2x×7x + 2x× -6 + 1×7x + 1×-6]
M = 11x - ( 14x² - 12x + 7x - 6)
M = 11x - ( 14x² - 5x - 6)
M = 11x - 14x² + 5x + 6
M = - 14x² + 16x + 6
Exercice 2 :
C= 5x-5*2
C = 5 ( x - 2)
D=2x²-3x
D = x ( 2x - 3)
E=7x²-14x
E = 7x×x - 2×7x
E = 7x ( x - 2)
Exercice 3 :
A= (2x+1)(-5x+3) - (x²+3)
A = 2x×-5x + 2x×3 + 1×-5x + 1×3 - x² - 3
A = - 10x² + 6x - 5x + 3 - x² - 3
A = - 11x² + x
b. A= - 11x² + x
A = x ( - 11x + 1)
c. Calculer A pour x= 1/11
A = - 11 × ( 1/11)² + 1/11
A = - 11 × 1/11 × 11 + 1/11 on simplifie on barre un 11 au numé
A = - 1 / 11 + 1/11 rateur et dénominateur
A = 0
