已知x-y+3,求3x²-6xy+3y²的值

已知x-y+3,求3x²-6xy+3y²的值
已知x-y+3,求3x²-6xy+3y²的值

已知x-y+3,求3x²-6xy+3y²的值
楼主你头像是诗诗啊,玉儿啊,也是小诗子吧
3x²-6xy+3y²
=3(x²-2xy+y²)
=3(x-y)²
=3×3²
=27

x-y=3

3x²-6xy+3y²
=3(x²-2xy+y²)
=3(x-y)²
=3×3²
=27