Répondre :
il faut réduire au maximum :
7y²+6y-5-(8y²-y+5)
=7y²+6y-5-8y²+y-5
=-y²+7y-10
=(5-y)(y-2)
7y²+6y-5-(8y²-y+5)
=7y²+6y-5-8y²+y-5
=-y²+7y-10
=(5-y)(y-2)