developer et reduire si possible svp merci d'avance exo 8

Bonjour,

(x + 8)(y + 2) = xy + 2x + 8y + 16

(7 - a)(x - 2b) = 7x - 14b - ax + 2ab

(5m + 4)(5m - 8) = 5m^2 - 40m + 20m - 32 = 5m^2 - 20m - 32

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

(x - 3y)(5x + y) = 5x^2 + xy - 15xy - 3y^2 = 5x^2 - 14xy - 3y^2

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

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