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Cours de Math 4eme
Calcul litteral
Identites remarquables- Identités remarquables
- (a + b)2 = a2 + 2ab + b2
- (a – b)2 = a2 -2ab + b2
- (a +b) (a – b) = a2 – b2
Exemples :
- (3x+5)
2
= (3x)2 + 2 x (3x) x 5 + 52
= 9x2 + 30x + 25
- (x + 6)(x - 6)
= x2 – 36
- (5x – 3)2
= (5x)2 – 2 x (5x) x 3 + 32
= 25x2 – 30x + 9
par felicite Djieukam