Bonjour ! ;)
Réponse :
A = (y + 2) (y - 2)
A = y² - 2²
A = y² - 4
B = (7 + x) (7 - x)
B = 7² - x²
B = 49 - x²
C = (3 + 10x) (10x - 3)
⇔ C = (10x + 3) (10x - 3)
C = (10x)² - 3²
C = 100x² - 9
D = (4 + 2x) (4 - 2x)
D = 4² - (2x)²
D = 16 - 4x²
E = (6y - 5) (6y + 5)
E = (6y)² - 5²
E = 36y² - 25
F = (8y - 1) (8y + 1)
F = (8y)² - 1²
F = 64y² - 1