Question

Cum se calculeaza trinomul:
(x+y-2) totul la puterea a doua.
Am nevoie rapid.

Answer 1

(x+y-2)^2=(x+y-2)(x+y-2)=x^2+xy-2x+yx+y^2-2y-2x-2y+4=x^2+y^2+z^2+2xy-4x-4y+4

Answer 2

(a+b-c)^2=a^2+b^2+c^2+2ab-2bc-2ca

deci:

(x+y-2)^2=x^2+y^2+4+2xy-4x-4y