Sagot :
Réponse :
A = (7x - 1)(2 - 3x) - 57 - 2x
14x -21x² - 2 + 3x = 21x² + 17x - 2
21x² = - 17x + 2
x² = (-17x + 2) / 21
B = (2x + 3) 2 + (3x + 4) (2 - 7x)
4x + 6 + 6x - 21 x² + 8 - 28x = 21x² - 24x + 14
21x² = 24x - 14
x² = 24x/21 - 14/21
C = 3(7x - 1)2 - (5 - 9x)2
(21x - 3)2 - 10 + 18x = 42x - 6 - 10 + 18x = 60x - 16
x = 16/60
D = (-7x + 3)2 - (5 - 9x)2
- 14x + 6 + (14x - 35x²)7 = - 14x + 6 + 98x - 245x²= -245x² + 84x + 6
F = -(11x - 13)2 + 7x(2 - 5x)7
- 22x + 26 + (14x - 35x²)7 = - 22x + 26 + 98x - 245x² = 245x² + 76x + 26
Explications étape par étape
