Réponses

2014-10-28T20:07:07+01:00
Bonsoir

3 ( 18 x² + 30 x - 15 x - 25) + ( 25 x² +20 x - 20 x - 16)
3 ( 18 x² + 15 x -25) + (25 x² - 16)
54 x² + 45 x - 75 + 25 x² -16
= 79 x² + 45 x - 91
2014-10-28T22:49:08+01:00

3(6x - 5) (3x + 5) + (5x - 4) (5x + 4)
= 3 (18x² + 30x - 15x - 25) + (25x² + 20x - 20x - 16)
= 3 (18x² +15x - 25) + (25x² - 16)
= 54x² + 45x - 75 + 25x² -16
= 79x² + 45x - 91