Bonjour aider moi svpppp

Bonjour

vrai ou faux ?

proposition 1 :

(a - b)(a + b)(a + b) = a^3 - b^3

(a - b)(a + b) = a^2 - b^2

(a - b)(a + b)(a + b) = (a^2 - b^2)(a + b)

(a - b)(a + b)(a + b) = a^3 + a^2b - ab^2 - b^3

faux

proposition 2 :

a^2 = 4 + (a + 2)(a - 2)

4 + (a + 2)(a - 2) = 4 + a^2 - 4

4 + (a + 2)(a - 2) = a^2

vrai