Réponses

2014-02-12T17:15:21+01:00
N= (4-3a)(a-5) + 15a
N = 4a-3a²-20+15a+15a
N = -3a² + 34a -20

S= (5+x)(x+4) + 3x(1-2x)
S = 5x+x²+20+4x +3x-6x²
S = -5x² +12x +20