Question

E(x) = (x+1)² + 2(x+1)(x−2)+(x−2)²

Answer 1

Răspuns:

(x²+2x+1)-2(x²-1)+(x²-2x+1)-x² =x²-2x²+x²-> +2x-2x+1+2+1

=-x²+4=4-x²

(2+x)(2-x)=2²-x²=4-x²