Réponse:
1/A=(2y-5)(1 + 3y) + 4y²– 25
=2y+6y²-5-15y+4y²-25
=10y²-13y-25
2/A=(2y-5)(1 + 3y) + 4y²– 25
=(2y-5)(1 + 3y)+(2y)²-5²
=(2y-5)(1 + 3y)+(2y-5)(2y+5)
=(2y-5)(1+3y+2y+5)
=(2y-5)(6+5y)
3/*y= -6/5
A=(2y-5)(6+5y)
=(2×-6/5-5)(6+5×-6/5)
=(-12/5-5)(6-30/5)
=(-12/5-5)(6-6)
=(-12/5-5)×0
=0
*y= 0.
A=(2y-5)(6+5y)
=(0-5)(6+0)
= -5×6
=-30