Réponses

2013-05-07T17:26:27+02:00
À=3 (x+5)(x-1)
= 3( x^2 +4x -5)
= 3x^2 +12x-15

2(-3-t)(t-7)
= 2( -3t +21-t^2 +7t)
= 2( -t^2 +4t+21)
= -2t^2 +8t+42
2013-05-07T17:48:07+02:00
Pour le A
3(x+1)(x-5)
(3x+1)(x-5)
3xcarre -15x+x-5
3xcarre-14x-5
pour le b
2(-3-t)(t-7)
(-6-2t)(t-7)
-6t+42-2t carré +14t
8t+42-2t carré
2t carré + 8t +42