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Bonsoir,
Est ce que les exercices sont bons ? merci.
Factorisations
A = (x-3)(8-7x)+(x-3)(-x-9)
A = (x-3)(8-7x-x-9)
A = (x-3)(-6x-1)
B = (5x-9)2 + (x+1)(5x-9)
B = (5x-9) (5x-9+x+1)
B = (5x-9)(6x-8)
C = (3x+2)(-2x-2)-(-3x-2)(6x+8)
C = (3x+2)[*(-2x-2)--(6x+8)]
C = (3x+2)(-2x-2+6x+8)
C = (3x+2)(4x+6)
D = 49x2 -9
D = (7x+3) (7x-3)
E = 25x2-70x+49
E = (5x-7)(5x-7)
F = (3x-1)2- 81
F impossible
G = (3x+3)(2x+7) - (9x2-9)
G = (3x+3)(2x+7) - (3x+3)(3x-3)
G = (3x+3) (2x+7 - 3x+3)
G = (3x+3) (-x+10)


Sagot :

A = (x-3)(8-7x)+(x-3)(-x-9)
A = (x-3)(8-7x-x-9)
A = (x-3)(-8x-1)
B = (5x-9)2 + (x+1)(5x-9)
B = (5x-9) (2+x+1)
B = (5x-9)(x+3)
C = (3x+2)(-2x-2)-(-3x-2)(6x+8)
C = (3x+2)[*(-2x-2)--(6x+8)] 
C = (3x+2)(-2x-2+6x+8)
C = (3x+2)(4x+6)  OK
D = 49x2 -9
D = (7x+3) (7x-3)  
 OK
E = 25x2-70x+49
E = (5x-7)(5x-7) = (5x - 7)²
F = (3x-1)2- 81
F (3x-1-9)(3x-1+9) = (3x-10)(3x+8)
G = (3x+3)(2x+7) - (9x2-9)
G = (3x+3)(2x+7) - (3x+3)(3x-3)
G = (3x+3) (2x+7 - 3x+3)
G = (3x+3) (-x+10)  
 OK
pas si mal!!!!!!