Réponses

2013-11-14T17:44:13+01:00
1) (a+b)² = a² +2ab + b²
(a-b)(a+b) = a²-b² 
(a-b)²= a²-2ab +b² 
2) (3x+2)² = 9x² + 12x+4
(5x-1)² = 25x² - 10x + 1 
(4x+3)(4x-3)=16x²-9 
2013-11-14T17:44:42+01:00
1)(a+b)²=a²+2ab+b²
(a-b)(a-b)=a²-ab-ab+b²
             =a²-2ab+b²
(a-b)²=a²-2ab+b²
2) (3x+2)²=9x²+12x+4
   (5x-1)²=25x²-10x+1
   (4x+3)(4x-3)=16x²-12x+12x-9
                     =16x²-9