Réponse :
A = 3(2x + 5) = 6x +15
6x = -15
x = 15/6
B = 2(6 - 3x) = 12 - 6x
6x = 12
x = 12/6 = 2
C = -4(-2x + 5) = 8x -20
8x = 20
x = 20/8 = 5/2
D = 3(2x + 4) + 5 (4x + 2) = 6x + 12 + 20x + 10 = 26x + 20
26x = - 20
x = -20/26 = -5/6
E = 4 (2x - 3) - 3 (5 - 6x) = 8x - 12 - 15 + 18x = 26x - 27
26x = 27
x = 27/26
F = (5x +6) + (4x + 2) = 5x + 6 + 4x + 2 = 9x + 8
9x = -8
x = -8/9
G = (2x - 5) - (5x + 3) = 2x - 5 - 5x - 3 = - 3x - 8
-3x = 8
x = - 8/3
H = (2x + 4)(4x + 2) = 8x² + 4x + 16x + 8 = 8x² + 20x + 8
I = (-4x + 6)(2x - 3) = - 8x² + 12x + 12x - 18 = - 8x² + 24x - 18
J = (2x + 3)(2x + 3) = 4x² + 6x + 6x + 9 = 4x² + 12x + 9
K = (3x - 4)(3x - 4) = 9x² - 12x -12x + 16 = 9x² - 24x + 16
L = (7x - 5)(7x + 5) = 49x² - 35x + 35x -25 = 49x² - 25
49x² = 25
x² = 25/29
x = racine carré de 25/29
M = (a + b)(a + b) = a² + ab + ab + b² = a² + b² + ab²
N = (a - b)(a - b) = a² - ab - ab + b² = a² + b² - ab²
O =(a + b)(a - b) = a² - ab + ab - b² = a² - b²
Explications étape par étape
