(x-2y)^2-(x+2y)^2=?

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(x-2y)^2-(x+2y)^2=?
(x-2y)^2-(x+2y)^2=?

(x-2y)^2-(x+2y)^2=?
应用平方差公式即可
(x-2y)^2-(x+2y)^2=(x-2y+x+2y)(x-2y-x-2y)=2x×(-4y)=-8xy
回答完毕,

(x-2y)^2-(x+2y)^2
=x²-4xy+4y²-(x²+4xy+4y²)
=x²-4xy+4y²-x²-4xy-4y²
=-8xy

(x-2y)^2-(x+2y)^2=-8xy

(x-2y)^2-(x+2y)^2
=x -4xy+4y -(x +4xy+4y )
=x -4xy+4y -x -4xy-4y
=-8xy