计算：（x-y）²-(y+2x)(y-2x)=______.

计算：（x-y）²-(y+2x)(y-2x)=______.
计算：（x-y）²-(y+2x)(y-2x)=______.

计算：（x-y）²-(y+2x)(y-2x)=______.
（x-y）²-(y+2x)(y-2x)
=x²-2xy+y²-y²+4x²
=5x²-2xy
如果本题有什么不明白可以追问,

（x-y）²-(y+2x)(y-2x)
=x^2-2xy+y^2-y^2+4x^2
=5x^2-2xy
=x(5x-2y)

5x²-2xy
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（x-y)²-(y+2x)(y-2x)
=x²-2xy+y²-(y²-4x²)
=x²-2xy+y²-y²+4x²
=5x²-2xy