Réponses

2013-11-16T13:12:23+01:00
A: (y+1) (y+1)
=y²+2y+1

b: (-3y+1) (-y-1)
=3y²+3y-y-1
=3y²+2y-1

c: (-a-1) (a-1)
=-a²+a-a+1
=-a²+1

d: (2x+1)(-3x+1)
=-6x²+2x-3x+1
=-6x²-x+1