原式=[(m-2n)(m+2n)]²-[(m-2n+m+2n)(m-2n-m-2n)]²=(m²-4n²)²-(-4mn)²=m⁴-8m²n²+16n⁴-16m²n²=m⁴-24m²n²+16n⁴=16-96+16=-64麻烦在写详细点，一步一步的可以吗？就是这样采纳吧