Question

Calculati (x+y)(x-y) daca x=(a+b)(a-b) si y=(c+d)(c-d)  va roooggggggggggggg

Answer 1

{(a+b)(a-b)}+{(c+d)(c-d)}
la patrat sunt toate:(a*-b*)+(c*-d*)-rezultatul final
,in loc de steluta pui 2

Answer 2

x=(a+b)(a-b)=a²-b²
y=(c+d)(c-d)=c²-d²

(x+y)(x-y)=x²-y²= (a²-b²)²-(c²-d²)²=(a²-b²+c²-d²)(a²-b²-c²+d²)