Разложите ** множители

Question

Разложите на множители

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Answer 1

1-4x²+8xy-4y²=1-4*(x²-2xy+y²)=1-4*(x-y)²=1²-(2*(x-y))²=(1-2*(x-y))*(1+2*(x-y))=
=(1-2x+2y)*(1+2x-2y).