pls imi trebuie urgent!! dau coroana!!!

Explicație pas cu pas:
E(x)=(x+3)²-2(x²+3x)+(x+1)²
E(x)=x²+2x•3+3²-(2x²+6x)+x²+2x+1
E(x)=x²+2x•3+3²-2x²-6x+x²+2x+1
E(x)=x²+6x+9-2x²-6x+x²+2x+1
E(x)=(x²-2x²+x²)+(6x-6x+2x)+(9+1)
E(x)=2x+10