Réponses

  • Utilisateur Brainly
2014-05-19T17:40:45+02:00
Exo 3 :

(3y-5)(1-5y) =
(3y*1 + 3y*-5y -5*1 -*-5y) =
3y-15y²-5+25y =
-15y²+28y-5

(-6-3x)(2-x) =
(-6*2 -6*-x -3x*2 -3x*-x) =
-12+6x-6x+3x² =
3x²-12 =
3(x²-4)