Réponses

2014-04-14T11:21:21+02:00
Bonjour,

A = (7x-3)(6x+1)
   = 42x² + 7x - 18x - 3
   = 42x² -11x - 3

B = (-2-9x)(-4y-1)
   = 8y + 2 + 36xy + 9x
   = 9x + 36xy + 8y + 2

C = (2x+3)(3-2x)
   = 6x - 4x² + 9 - 6x
   = -4x² + 9

D = (-10-3a)(2a-9)
    = -20a + 90 - 6a² + 27a
    = -6a² + 7a + 90