Bonsoir ;
On essaiera de faire le maximum .
Exercice n° 1 :
1)
A = 5x² - x = x(5x -1) .
B = x(2x + 4) + (2x + 4)(-7x - 1) = (2x + 4)(x - 7x -1)
= (2x + 4)(-6x - 1) = 2(x + 2)(-6x - 1) = -2(x + 2)(6x + 1) .
C = (x - 2)² - (4x + 1)² = (x - 2 - 4x - 1)(x - 2 + 4x + 1)
= (-3x - 3)( 5x - 1) = -3(x + 1)(5x - 1) .
2)
D = (9 - x)² = 9² - 2 * 9 * x + x² = x² - 18x + 81 .
E = (x + 4)(7 - 6x) = 7x - 6x² + 28 - 24x
= -6x² - 17x + 28 .
F = 2x - 3 - (x + 6)(6 - x) = 2x - 3 + (x + 6)(x - 6)
= 2x - 3 + x² - 6² = 2x - 3 + x² - 36 = x² + 2x - 39 .
