Répondre :
(5x-3)²-81 = (5x-3)²-9²
= (5x-3+9)(5x-3-9)
= (5x+6)(5x-12)
Voila ;)
= (5x-3+9)(5x-3-9)
= (5x+6)(5x-12)
Voila ;)
Factoriser
Tu entoure (5x-3)
et tu ecrit :
(5x-3) (5x-3-81)
(5x-3) (-79x)
Voila