Réponses

2012-10-17T20:03:15+02:00

A:a(5x-1)^2*-(5x-1)(x+3)

factoriser

(5x-1)(a(5x-1)-x-3)=(5x-1)(5ax-a-x-3)

dévellopé

a(25x^2-10x+1)-(5x^2+15x-x-3)=25ax^2+10ax+a-5x^2-14x+3=25ax^2-5x^2+10ax-14x+a+3

si x=2

100a-20+20a-28+a+3  121a=45     a=45/121 

bonne chance