Bonjour,
1)
P = (3x - 2)² - (3x - 2) (- 5x + 3)
P = 9x² - 12x + 4 - (- 15x² + 9x + 10x - 6)
P = 9x² - 12x + 4 + 15x² - 9x - 10x + 6
P = 9x² + 15x² - 12x - 9x - 10x + 4 + 6
P = 24x² - 31x + 10
2)
(3x - 2)² - (3x - 2) (- 5x + 3)
= (3x - 2) [(3x - 2) - (- 5x + 3)]
= (3x - 2) (3x - 2 + 5x - 3)
= (3x - 2) (8x - 5)
3 )
P = 0
P = (3x - 2) (8x - 5) = 0
3x - 2 = 0 ou 8x - 5 = 0
3x = 2 8x = 5
x = 2/3 x = 5/8
4)
P = 10
3x - 2 = 10 ou 8x - 5 = 10
3x = 10 + 2 8x = 10 + 5
3x = 12 8x = 15
x = 12/3 x = 15/8
x = 4