x+y=1,则0.5x²+xy+0.5y²= ?

x+y=1,则0.5x²+xy+0.5y²= ?
x+y=1,则0.5x²+xy+0.5y²= ?

x+y=1,则0.5x²+xy+0.5y²= ?
0.5x²+xy+0.5y²
=2(1/2x²+xy+1/2y²)/2
=(x²+2xy+y²)/2
=(x+y)^2/2
=1/2
本题用的完全平方的知识,