0.5x²+xy+0.5y²
问题描述：
0.5x²+xy+0.5y²
答
0.5x²+xy+0.5y²
=0.5(x^2+2xy+y^2)
=0.5(x+y)^2
0.5x²+xy+0.5y²
0.5x²+xy+0.5y²
=0.5(x^2+2xy+y^2)
=0.5(x+y)^2