Réponses

  • Utilisateur Brainly
2014-03-24T19:41:57+01:00
a=(2x + 5)² + (x-4)²
  =4x²+20x+25+x²-8x+16
   =5x²+12x+41

b= (x +5) (x-9) - (x+5) (3x+7)

  =(x+5)(x-9-3x-7)
  =(x+5)(-2x-16)
  =-2(x+5)(x+8)
  =-2(x²-13x+40)
  =-2x²+26x-80