Réponse :
Il faut utiliser les identités remarquables.
A = 16x² + 56x + 49
A = 4²*x² + 2*4*7 + 7²
A = (4x + 7)²
B = - (5x+7)²+1
B = 1²-(5x+7)²
B = [-(5x+7)+1] [-(5x+7)-1]
B = (-5x-7+1) (5x+7-1)
B = (-5x-8) (5x+6)
C = -(2x-1)(4x+3)+(5x-8)(4x+3)
C = (4x+3)[-(2x-1)+(5x-8)]
C = (4x+3)(3x-9)
D = -100x²+81
D = 81-100x²
D= 9²-(25x)²
D = (9+25x)(9-25x)
E = (6x + 2)² + (5x+1) (6x+2)
E = (6x + 2)(6x + 2)² + (5x+1)(6x+2)
E = (6x+2) [(6x+2) + (5x+1)]
E = (6x+2) (11x + 3)
F = (10x+3)(10x-10) + 10x-10
F = (10x+3)(10x-10) + (10x-10)*1
F = (10x-10)[(10x+3)+1]
F = (10x-10)( 10x+4)
EXERCICE 2
1. 3,809*10
2. 8,803*10000000
3. 3,30 * 10000000
4. 6,086 *1000
5. 1,3 *0,000001
6. 6,098 *10
