Réponses

  • Omnes
  • Modérateur confirmé
2014-03-03T22:21:06+01:00
Salut,

A = (y+5)(y-2) - 6(y+5)

a. A = (y+5)(y-2) - 6(y+5)
A = y² - 2y + 5y - 10 - (6y + 30)
A = y² + 3y - 10 -6y -30
A = y² -3y -40

b.
A = (y+5)(y-2) - 6(y+5)
A = (y+5)(y-2 - 6)
A = (y+5)(y-8)

c.
(y+5)(y-8) = 0
y + 5 = 0
y = -5

y - 8 = 0
y = 8

S={-5;8}

Bonne soirée!