14x - 21y
= 7 * 2 * x - 7 * 3 * y
= 7 (2x - 3y)
9x² + 6x + 1
= (3x)² - 2 * 3 * x + 1²
= (3x + 1)²
16x² - 24x + 9
= (4x)² - 2 * 12 * x + 3²
= (4x - 3)²
(5x + 1) (3x + 1) + (5x + 1) (7x - 6)
= (5x + 1) [(3x + 1) + (7x - 6)]
= (5x + 1) (3x + 1 + 7x - 6)
= (5x + 1) (10x - 5)
36x² - 25
= (6x)² - 5²
= (6x - 5) (6x + 5)
81x² + 144x + 64
= (9x)² + 2 * 72 * x + 8²
= (9x + 8)²
x² - 3
--> Je pense qu'on ne peut pas factoriser cette expression.
