Réponses

2013-09-18T15:44:22+02:00
1) A= (2x+1)(x-5)
= 2x * x + 2x * (-5) + 1 * x + 1 * (-5)
 2x^{2} + (-10x) + 1x + (-5)
 2x^{2} + (-9x) + (-5)

2) A= (2 * 3+1)(3-5)
= (6 + 1) * (-2)
= 7 * (-2)
= -14

3) A= (2 * 0 +1)(0-5)
= (0 + 1) * (-5)
= 1 * (-5)
= -5
2013-09-18T15:48:47+02:00
1)
a=(2x+1)(x-5)
( 2x*x+2x*(-5) ) + 1*x+1*(-5) 
2x²+10x+1x+(-5)
2x²+11x-5