Salut !

Réponse :

A = 5x -2) x (3x + 2) -2 (x+1) x (5x -2)

A = (5x -2) x (3x = 2 - 2 ( x + 1))

A = (5x - 2) x (3x + 2 - 2x -2)

A = (5 x - 2) x

A = X x (5x-2)

B = (6x - 9) x (x + 2) + (2x -3) x (x+7)

B = 6 x² + 12 x - 9 x - 18 + (2x -3) x (x+7)

B = 6 x² + 12 x - 9 x - 18 + 2x² + 14 x -3x - 21

B = 8x² + 12 x - 9x - 18 + 14x - 3x - 21 donc 8x² + 14 x - 18 - 21

B = 8x² + 14x - 39

C = 5 (x+2)² - (x + 2) x  (5x +6)

C = (x+ 2) x (5(x+2) - (5 x 6))

C = (x + 2) x 5x + 10 - 5x -6)

C = ( x + 2) x 4

C = 4(x+2)

D = (3x - 1) x (x+2) + (3 x -1)²

D = (3 x - 1) x (x + 2 + 3x - 1)

D = (3x - 1) x (4x + 2 - 1)

D = (3x - 1) x 4x + 1

D = (3x - 1) x (4x + 1)

E = 6x + (5x - 2) x (3x + 2) + 4

E = 2 ( 3x + 2) + (5x - 2) x (3x + 2)

E = (3x + 2) x (2 + 5x - 2)

E = ( 3x + 2) x 5x

E = 5x x (3x +2)

F = 64 + 80 x + 25x² - (8+5x) x ( 4x + 3)

F = 64 + 80 x + 25x² - ( 32 x + 24 + 20x² + 15x)

F = 64 + 80 x + 25x² - ( 47x + 24 + 20x²)

F = 40 + 33 x + 5x²

F = 5x² + 33x + 40

G = (2x + 3) x (8- 2x) + 4x² -9

G = (2x + 3) x (8- 2x) x (2x - 3) x (2x + 3)

G = (2x + 3) x (8- 2x + 2x - 3)

G = (2x + 3) x 5

G = 5 (2x + 3)

H = (8x + 1)² - 5x + 9)²

H = (8x + 1 - ( 5x + 9)) x (8x + 1 + (5x + 9))

H = (8x + 1 - 5x - 9) x (8x + 1 + 5x + 9)

H = (3x + 1 - 9) x (8x + 1 + 5x + 9) puis (3x - 8) x (8x + 1 + 5x + 9) et enfin

(3x - 8) x (13x + 1 + 9)

H =  (3x - 8) x (13x + 10)

Bonne journée et bon courage : )