问题
填空题
计算:(x-2y)2-(2x-y)(2x+y)=______.
答案
(x-2y)2-(2x-y)(2x+y)=
=x2+4y2-4xy-4x2+y2,
=-3x2-4xy+5y2.
故答案为:-3x2-4xy+5y2.
计算:(x-2y)2-(2x-y)(2x+y)=______.
(x-2y)2-(2x-y)(2x+y)=
=x2+4y2-4xy-4x2+y2,
=-3x2-4xy+5y2.
故答案为:-3x2-4xy+5y2.