Bonjour,
1.
11x - (2x + 3) = 2x - 3
11x - 2x - 3 = 2x - 3
11x - 2x - 2x = - 3 + 3
7x = 0
x = 0
2.
(15x - 3) (- 7x + 28) = 0
15x - 3 = 0 ou - 7x + 28 = 0
15x = 3 ou - 7x = - 28
x = 3/15 ou x = 28/7
x = 1/5 ou x = 4
3.
4x² = 29
4x² - 29 = 0
Je ne vois pas ce qu il faut faire...
4.
(1 - 5x)²
= (1 - 5x) (1 - 5x)
5.
5x (6x - 1) = (10x - 7) (3x + 1)
30x² - 5x = 30x² + 10x - 21x - 7
30x² - 30x² - 5x - 10x + 21x = - 7
6x = - 7
x = - 7/6
