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
