Răspuns:
(x^2+2x+2x+4) +(x^2+3x+3x+9) -(2x^2+4x+x+2) =
= x^2+4x+4 + x^2+6x+9-2x^2-5x-2
(X^2 + x^2 -2x^2 se elimina pt ca =0 )
= 5x+11
X^2 = x la puterea a doua (x patrat )