求x^2-4xy-1+4y^2的解

问题描述:

求x^2-4xy-1+4y^2的解
x^2-4xy-1+4y^2

(x-2y+1)(x-2y-1)过程呢?(x-2y)^2-1 = (x-2y)^2-1^2 = (x-2y+1)(x-2y-1)