分解因式[2x-y]-[y-2x]2

=2x-y-2y+4x
=6x-3y
=3(2x-y)

(2x-y)-(y-2x)^2
=(2x-y)-(2x-y)^2
=(2x-y)[1-(2x-y)]
=(2x-y)(1-2x+y)

因式分解大多有公式不需拆项 所以1 2楼错误 3楼更是错 首先 平方内改变正负不需要改变符号，其次 (2x-y)^2=(2x-y)(2x-y)，而并非2(2x-y).

(2x-y)-(y-2x)2

=(2x-y)-(2y-4x)

=2x-y-2y+4x

=6x-3y

[2x-y]-[y-2x]2
=(2X-Y)+(2X-Y)2
=(2X-Y)(1+2)
=3(2X-Y)