Question

Exemple:formule de calcul prescurtat

Answer 1

$(a+sau-b)^{2}$=$a^{2}+sau-2ab+ b^{2}$
(a+b)(a-b)=$a^{2} - b^{2}$
$(a+b+c)^{2} = a^{2} + b^{2} + c^{2} +2ab+2ac+2cb$
coroana?