Réponses

2014-01-13T18:05:16+01:00
 A=(x²+5x-3)+(x²-x+7)
=x²+5x-3+x²-x+7
=2x²+4x+4

B=-(x²+6x-3)+( x²+2x+1)
=-x²-6x+3+x²+2x+1
=-4x+4