Bonjour,
(a + b)² = a² + 2ab + b²
(a - b)² = a² - 2ab + b²
(a + b)(a - b) = a² - b²
a. (x + 4)² = x² + 8x + 16
b. (y - 3)² = y² - 6y + 9
car 6y = y * 2 * 3
c. (k + 6)(k - 6) = k² - 36
d. (3x + 2)² = 9x² + 12x + 4
car 4 = 2²
e. (1 - 7x)(1 + 7x) = 1 - 49x²
car 49x² = 7x * 7x
f. (3x - 8)² = 9x² - 48x + 64
car 48x = 2 * 8 * 3
g. (10y + 3)(10y - 3) = 100y² - 9
car 100y² = 10y * 10y
