已知x2-xy=7,2xy+y2=4,则代数式x2+xy+y2的值是_.
问题描述:
已知x2-xy=7,2xy+y2=4,则代数式x2+xy+y2的值是___.
答
∵x2-xy=7,2xy+y2=4,
∴原式=(x2-xy)+(2xy+y2)=7+4=11,
故答案为:11