Réponses

2012-10-24T18:55:08+02:00

(2x+4)²-(x+2)(-4x+7)=2²(x+2)²-(x+2)(-4x+7)=(x+2)(4(x+2)-4x+7)=(x+2)(4x+8-4x+7)

=(x+2)(15)=15(x+2)