A = 4(x + 3) - 2(8x - 1)

A = 4x + 12 - 16x + 2

A = -12x + 14

B = (5x + 7)(3 - x)

B = 15x - 5x² + 21 - 7x

B = 5x² + 8x + 21

C = (2x + 3)(x - 5) - (4x - 1)(x - 9)

C = 2x² - 10x + 3x - 15 - [4x² - 36x - 1x + 9]

C = 2x² - 10x + 3x - 15 - 4x² + 36x + 1x - 9

C = - 2x² + 30x - 24

D = - 5 (x - 7) + (4x - 2)(7 - 3x)

D = - 5x + 35 + 28x - 12x² - 14 + 6x

D = -12 x² + 29x + 21

E = (x + 3)(x - 5) - (-1 + x)(x - 9)

E = x² - 5x + 3x - 15 - [-1x + 9 + x² - 9x]

E = x² - 5x + 3x - 15 + 1x - 9 - x² + 9x

E = 8x - 24

A = x² - 8x² - 9x² - 3x - x + 6x - 12 + 1

A = - 16x² + 2x - 11

B = 5x² - 9x + 2 - 7x² - 5x + 4 - x²

B = - 3x² - 14x + 6

G = (x + 5)(7x - 3) + (x + 5)(2x - 4)

G = (x + 5) x [(7x - 3) + (2x - 4)]

G = (x + 5) x (7x - 3 + 2x - 4)

G = (x + 5)(9x - 7)

G = 9x² - 7x + 45x - 35

G = 9x² + 38x - 35

H = (x + 3)(x + 4) - 6(x + 4)

H = x² + 4x + 3x + 12 - 6x - 12

H = x² + x

I = (x + 7)(2x + 1) - (9x + 4)(2x + 1)

I = (2x + 1) x [(x + 7) - (9x + 4)

I = (2x + 1) x (x + 7 - 9x - 4)

I = (2x + 1)(-8x +3)

I = -16x² + 6x - 8x + 3

I = 16x² - 2x + 3

J = (3x - 5)² + (3x - 5)(7x - 4)

J = (3x)² - 2 x 3x x 5 + 5² + 21x² - 12x - 35x + 20

J = 9x² - 30x + 5 + 21x² - 12x - 35x + 20

J = 30x² - 77x + 25

K = (3x + 2)² - (3x + 2)(x + 7)

K = (3x)² + 2 x 3x x 2 + 2² - [3x² + 21x + 2x + 14]

K = 9x² + 12x + 4 - 3x² - 21x - 2x - 14

K = 3x² - 11x - 10

L = (5x + 3)² - (5x + 3)(2x - 4)

L = (5x)² + 2 x 5x x 3 + 3²- [10x² - 20x + 6x - 12]

L = 25x² + 30x + 9 - 10x² + 20x - 6x + 12

L = 15x² + 44x + 21

M = (3x + 2)(4x + 1) - (4x + 1)²

M = 12x² + 3x + 8x + 2 - [(4x)² + 2 x 4x x 1 + 1²]

M = 12x² + 3x + 8x + 2 - 16x² - 8x - 1

M = -4x² + 3x + 2

N = (x + 3)² + (x + 3)

N = x² + 2 x x x 3 + 3² + x + 3

N = x² + 6x + 9 + x + 3

N = x² + 7x + 12

Ouf ! voilà pour toi. Bonne chance ! :) ;)