Réponses

2013-11-12T22:25:16+01:00
(7x-1)(x+1)
=7x²+7x-x-1
=7x²+6x-1

3(2-x)(6x-1)
=3(12x-2-6x²+x)
=36x-6-18x²+3x
=-18x²+39x-6

2(1-x)²
=2(1-2x+x²)
=2-4x+2x²
=2x²-4x+2

(2x+1)(3x-2)(x+2)
=(2x+1)(3x²+6x-2x-4)
=(2x+1)(3x²+4x-4)
=6x³+8x²-8x+3x²+4x-4
=6x³+11x²-4x-4

(x-1)²+3(1-3x)(x+3)
=x²-2x+1+3(x+3-3x²-9x)
=x²-2x+1+3x+9-9x²-27x
=-8x²-26x+10

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

x²-144-3(x+12)
=(x+12)(x-12)-3(x+12)
=(x+12)(x-12-3)
=(x+12)(x-15)

x²-12x+36
=(x-6)²

9x²-49
=(3x+7)(3x-7)