bonjour
on factorise par le facteur commun .
a)
(3x-1) [3x-1-(-5x+2)]
= (3x-1)(3x-1+5x-2)
= (3x-1)(8x-3)
b)
(-2x+6)( 2x+13-4x+3)
=(-2x+6)(16-2x)
= 2(-x+3)(2)(8-x)
= 4(8-x)(-x+3)
c)
(-b+12) (5b-6+3b-1)
=(-b+12)(8b-7)
d)
(x-3)(2x-11-x+18)
=(x-3)(x+7)
e)
(3y²-1) (y²+6+2-3y²)
=(3y²-1) (-2y²+8)
=-2(3y²-1)(y²-4)
= -2(3y²-1) (y-2)(y+2) identité remarquable a²-b² =(a-b)(a+b)
= -2(√3y-1)(√3y+1)(y-2)(y+2)
f)
(x-1)(x²+3+x-1)
=(x-1) (x²+x+2)
