Aider moi svp c grave urgennnt SVPPPPP TOUUT LES EXEERCICEE SVPP

(a+b)(c+d) =ac +ad+bc+bd
k(a+b) = ka+kb

exercice 2

a = 7 ( -x +2x) + (2x-7) +15x
a = -7x +14x +2x -7 +15x
a = 24x -7

b = -3(-5x+3) +3 (-x+2x)
b = 15x -9 -3x +6x
b = 18x -9

c = 4 (x +5)
c = 4x +20

d = ( -3x-7) (9-3x)
d = -27x +9x²-63+21x
d = 9x² -6x -63

Exercice 1
Développer et réduire les expressions suivantes :

A = 7 ( -x + 2x) + (2x - 7) +15x
A = - 7x + 14x + 2x -7 + 15x
A = - 7x + 31x - 7
A = 24x - 7

B = - 3 (-5x + 3) +3 (-x + 2x)
B = 15x - 9 - 3x + 6x
B = 21x - 3x - 9
B = 18x - 9

C = 4 (x + 5)
C = 4x + 20

D = (-3x - 7) (9 - 3x)
D = -27x + 9x² - 63 + 21x
D = 9x² - 6x - 63

Exercice 2 :
Factoriser :

E = 25 + 21x
?

F = 35x - 5x
F = 5 (7x - x)