Bonjour, pouvez vous m'aider à faire cet exercice.Merci beaucoup.

Bonsoir,

1)
A = (3x - 2)² - (3x - 2)(x - 3)
A = (3x)² - 12x + 2² - (3x² - 9x - 2x + 6)
A = 9x² - 12x + 4 - 3x² + 9x + 2x - 6
A = 9x² - 3x² - 12x + 9x + 2x + 4 - 6
A = 6x² - x - 2

2) soit x = -2/3
A = 6 * (-2/3)² - (-2/3) - 2
A = 6 * (-2)²/3² + 2/3 - 2
A = 6 * 4/9 + 2/3 - 2
A = 6/1 * 4/9 + 2/3 - 2
A = 24/9 + 2/3 - 2
A = 24/9 + (2 x 3)/(3 x 3) - 2
A = 24/9 + 6/9 - 2
A = 30/9 - 2
A = 30/9 - 2/1
A = 30/9 - (2 x 9)/(1 x 9)
A = 30/9 - 18/9
A = 12/9
A = (12 ÷ 3)/(9 ÷ 3)
A = 4/3