Réponse :
EXERCICE 1
A = 8x + 11x - 5 = 19x - 5 19x = 5 x=5/19
B = 9a - 11 + 6a + 4 = 15a - 7 15a=7 a=7/15
C = -7 * 2x = -14x
D = 7 + 5x 5x=7 x=7/5
E = -6x * 3x = -18x²
F = 3b * 5b -2b * 8 = 15b² - 16b
G = -3c² + 5c - 13 + 7c² - 8c + 21 = 4c² - 3c + 8
H = (3y-7) - (6y+3) = 3y - 7 - 6y - 3 = - 3y - 10 -3y=10 y=10/-3
I = 4x - (-5 + 6x) = 4x + 5 - 6x = -2x + 5 -2x=-5 x=5/2
EXERCICE 2
-2a + 13a = 11a
7a * -3a = -21a²
-8a - 7a = -15a
7 * -4a² = -28a²
EXERCICE 3
J = 2(3x-1) = 6x - 2
K = -3m(3 + 7m) = - 21m² - 9m
L = 7 + (2y + 3) * 2 = 7 + 4y + 6 = 4y + 13
M = 7(2x + 3) + 2x(5x - 8) = 14x + 21 + 10x² - 16x = 10x² - 2x + 21
N = 10(-2 + 6x) - 5x(3x + 4) = -20 + 60x - 15x² - 20x = -15x² + 40x - 20
F = 7x(9x - 2) + 1 = 63x² - 14x + 1
EXERCICE 4
A = 3x + 6 = 3(x + 2)
B = 30 - 12x = 6(5 - 2x)
C = 14x² + 11x = x(14x + 11)
D = 9a² - 6a + 12 = 3(3a² - 2a + 4)
E = 8x + 24x² = 8x(1 + 3x)
EXERCICE 5
1) Programme A : (-1) * 3 = -3 +6 = 3 *2 = 6
2) Programme B : (-1) +2 = 1 *6 = 6
3) (3x + 6)*2 = (x + 2)*6
6x + 12 = 6x + 12 VRAI
Explications étape par étape :
