【[2x+y]的二次方+[2x-y]的二次方】[2 - 知识问答

【[2x+y]的二次方+[2x-y]的二次方】[2x的二次方-二分之一y的二次方]

1个回答

原式
=(4x²+4xy+y²+4x²-4xy+y²)·1/2·(4x²-y²)
=2(4x²+y²)·1/2·(4x²-y²)
=(4x²+y²)(4x²-y²)
=16x⁴-y⁴
=16×(-3)⁴-4⁴
=16×81-256
=1040

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