若x+y=1,则代数式1/2x²+xy+1/2y²的值为

问题描述:

若x+y=1,则代数式1/2x²+xy+1/2y²的值为

1/2x²+xy+1/2y²
=1/2(x²+2xy+y²)
=1/2(x+y)²
=1/2×1
=1/2
够详细了吧,