题设:(5m²+3n²)²-(3m²+5n²)²
=(5m²+3n²+3m²+5n²)(5m²+3n²-3m²-5n²)
=(8m²+8n²)(2m²-2n²)
=16(m²+n²)(m²-n²)
=16m^4-16n^4
即16乘以m的4次方,减去16乘以n的4次方.
题设:(5m²+3n²)²-(3m²+5n²)²
=(5m²+3n²+3m²+5n²)(5m²+3n²-3m²-5n²)
=(8m²+8n²)(2m²-2n²)
=16(m²+n²)(m²-n²)
=16m^4-16n^4
即16乘以m的4次方,减去16乘以n的4次方.