解：原式=2（x²+2x+1）-1/2（x²-4）=2x²+4x+2-1/2x²+2=3/2x²+4x+4
2(x+1)^2-1/2(x+2)(x-2)=2(x²+2x+1)-1/2(x²-4)=2x²+4x+2-1/2X²+2=3/2X²+4X+4
2(x+1)^2-1/2(x+2)(x-2)=2x^2+4x+2-1/2(x^2-4)=2x^2+4x+2-x^2/2+2=5x^2/2+4x+4
