设z=x/y.
原式=y^2(z^2-4z+2)
=y^2(z^2-4z+2)
=y^2(z-2+√2)(z-2-√2)
=y^2(x/y-2+√2)(x/y-2-√2)
=(x-2y+y√2)(x-2y-y√2).
把多项式x²-4xy+2y²分解因式,得——
设z=x/y.
原式=y^2(z^2-4z+2)
=y^2(z^2-4z+2)
=y^2(z-2+√2)(z-2-√2)
=y^2(x/y-2+√2)(x/y-2-√2)
=(x-2y+y√2)(x-2y-y√2).