Bonjour pouvez vous m aider a factoriser 30-12 ; 16x²+20x ; 9a²-3a ; 18x²-30x+36 ; x²+6x+9 ; 25x²-40x+16 ; 36x²-1 ; 9-12x+4x² ; (2x+1)(3x-1)-(2x+1)(3x+2) ; 'x-6²)+(x+3)(x-6) ; 9-(x+2)² ; x²-25-(3x+1)(x-5) ; (5x+3)(x-2)+x²-4x+4 ; (2+x²)-(4x+5)² merci beaucoup

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2014-05-05T09:52:09+02:00
30-12
=6(5-2)

16x²+20x
=4x(4x+5)

9a²-3a
=3a(3a-1)

18x²-30x+36
=6(3x²-5x+6)

x²+6x+9
=(x+3)²

25x²-40x+16
=(5x-4)²

36x²-1
=(6x+1)(6x-1)

9-12x+4x²
=(3-2x)²

(2x+1)(3x-1)-(2x+1)(3x+2)
=
(2x+1)(3x-1-3x-2)
=(2x+1)(0x-3)
=-3(2x+1)

(x-6)²+(x+3)(x-6)
=
(x-6)(x-6)+(x+3)(x-6)
=(x-6)(x-6+x+3)
=(x-6)(2x-3)

9-(x+2)²
=[3-(x+2)]
[3+(x+2)]
=(3-x-2)(3+x+2)
=(-x+1)(x+5)

x²-25-(3x+1)(x-5)
=
(x-5)(x+5)-(3x+1)(x-5) 
=(x-5)[x+5-(3x+1)]
=(x-5)(x+5-3x-1)
=(x-5)(-2x+4)
=2(x-5)(-x+2)

(5x+3)(x-2)+x²-4x+4
=
(5x+3)(x-2)+(x-2)²
=(5x+3)(x-2)+(x-2)(x-2)
=(x-2)(5x+3+x-2)
=(x-2)(6x+1)

(2+x)²-(4x+5)²
=[
(2+x)-(4x+5)][(2+x)+(4x+5)]
=(2+x-4x-5)(2+x+4x+5)
=(-3x-3)(5x+7)
=-1(x+1)(5x+7)