(5m²+3n²)²-(3m+5n)²
=[(5m²+3n²)-(3m+5n)][(5m²+3n²)+(3m+5n)]
=(5m²+3n²-3m-5n)(5m²+3n²+3m+5n)
=(5m²+3n²-3m-5n)(5m²+3n²+3m+5n)
a²(a-b)+b²(b-a)
=a²(a-b)-b²(a-b)
=(a²-b²)(a-b)
=(a+b)(a-b)(a-b)
=(a+b)(a-b)²
(5m²+3n²)²-(3m+5n)²
=[(5m²+3n²)-(3m+5n)][(5m²+3n²)+(3m+5n)]
=(5m²+3n²-3m-5n)(5m²+3n²+3m+5n)
=(5m²+3n²-3m-5n)(5m²+3n²+3m+5n)
a²(a-b)+b²(b-a)
=a²(a-b)-b²(a-b)
=(a²-b²)(a-b)
=(a+b)(a-b)(a-b)
=(a+b)(a-b)²