Sagot :
Réponse :
A = (x + 5) ² = (a+b)² =a²+2ab+b²
A =x²+10x+25
B = (3x – 7) ² = (a-b)² =a²-2ab+b²
B = 9x²-42x+49
C = (x + 4) (x – 4) =(a+b)(a-b) =a²-b²
C =x²-16
D = (9b + 7) ²= (a+b)² =a²+2ab+b²
D = 81b²+126b+49
E = (7x + 1) (7x – 1)=(a+b)(a-b) =a²-b²
E = 49x²-1
Explications étape par étape :
Bonjour,
Rappel sur les identités remarquables
(a + b)² = a² + 2ab + b²
(a - b)² = a² - 2ab + b²
a² - b² = (a + b)(a - b)
Explications étape par étape:
A = (x + 5) ²
A = x² + 10x + 25
B = (3x – 7) ²
B = 9x² - 42x + 49
C = (x + 4) (x – 4)
C = x² - 16
D = (9b + 7) ²
D = 81b² + 126b + 49
E = (7x + 1) (7x – 1)
E = 49x² - 1