Réponses

2013-04-06T15:10:11+02:00

A = (x + 2)(x - 3) + (x - 3)

A = x² - 3x + 2x - 6 + x - 3

A = x² - 9

 

B = (2x - 3)²

B= 4x² - 12x + 9

 

Si x = 3 alors :

A = x² - 9

A = 3² - 9

A = 9 - 9

A = 0

 

Si x = 1,5 alors :

B = 4x² - 12x + 9

B = 4*(1,5)² - 12*1,5 + 9

B = 4*2,25 - 18 + 9

B = 9 - 18 + 9

B = 0