x³-4x²y+4y²x=x(x²-4xy+4y²)=x(x-2y)²
(x³-4x²y+4y²x)/(x-2y)=x(x-2y)²/(x-2y)=x(x-2y)
如果是√[(x³-4x²y+4y²x)/(x-2y)]
=√[x(x-2y)]
如果是√(x³-4x²y+4y²x)/(x-2y)
=(x-2y)√x/(x-2y)
=√x第一种那最后的答案就是√[(x³-4x²y+4y²x)/(x-2y)]=√[x(x-2y)]