Bonjour j’ai un dm de math pour la rentrée mais je n’arrive pas à faire c’est exercice vous pouvez m’aider svp

Exercice 1 :

A = 3x -8 +4x +5
A = 7x -3

B = 3x^2 +5x -6 -2x^2 -4x -3
B = x^2 +1x -9

C = 5x^2 -7 -9x^2 +x -3x +9
C = -4x^2 -2x +2

D = 4x^2 -(5x +x^2 -6x) +7x
D = x (3x +8)

E = 3x -(4 +2x) + (x^2 +7)
E = x^2 +x +3

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


Exercice 2 :

A = 7(x+4)
A = 7x +28

B = 4(3 -2x)
B = 7 -8x

C = -3(x +7)
C = -3x -21

D = -5(3x -2)
D = -15x +10

E = -2x(5+4x)
E = -10x -8x donc -18x

F = 3x^2(1-2x)
F = 3x^2 -6x^3


Exercice 3 :

A = (x +2)(x +3)
A = x^2 +5x +6

B = (x -7)(3x -2)
B = 3x^2 -23x -14

C = (1 +2x)(3 -x)
C = 2x^2 +5x +3

D = (-7x +6)(5 -x^2)
D = (7x -6)(x^2 -5)

E = (3x +4)(-x +1)
E = -3x^2 -1x +4

F = (3x^2 -4)(2x +5)
F = 6x^3 +15x^2 -8x -20