：(m+n)(m-n)[mn-(m+n)²][(m-n)²+mn]=(m+n)(m-n)[mn-(m²+2mn+n²)(m²-2mn+n²+mn)=-(m+n)(m²-mn+n²)(m-n)(m²+mn+n²)=-(m³+n³)(m³-n³)=-(m^6-n...