Bonjour
1) A = (x - 1)² + (x - 1) (2x - 3)
A = x² - 2x + 1 + 2x² - 3x - 2x + 3
A = x² + 2x² - 2x - 2x - 3x + 1 + 3
A = 3x² - 7x + 4
2) A = (x - 1)² + (x - 1) (2x - 3)
A = (x - 1) (x - 1 + 2x - 3)
A = (x - 1) (3x - 4)
3) (x - 1) (3x - 4) = 0
x - 1 = 0 ou 3x - 4 = 0
x = 1 3x = 4
x = 4/3.
