已知x-y=4,x-3y=1,则x2-4xy+3y2的值为_.

问题描述:

已知x-y=4,x-3y=1,则x2-4xy+3y2的值为______.

∵x-y=4,x-3y=1,
∴x2-4xy+3y2=(x-y)(x-3y)=4.
故答案为:4