Réponses

2013-01-04T16:50:55+01:00

1) (2x+3)²+ 2x X 7x + 2x X -2 + 3 X 7x + 3 X -2

= 4x² + 12x + 9 + 14x² - 4x + 21x - 6 

= 18x² + 29x + 3 .