# How can transform a product into sum of two squares

How can I transform the product 365(15^2+16^2) into sum of two squares???

• There are sixty-four different integer solutions to $x^2+y^2=365(15^2+16^2)$... are you looking for any particular solution or all of them? – JMoravitz Nov 22 '16 at 7:48
• Any of them. I need the method. – Avirup Biswas Nov 22 '16 at 7:50

As $365=5\cdot73$
$5=1^2+2^2$
$73=8^2+3^2$
Use Brahmagupta-Fibonacci Identity $$(a^2+b^2)(c^2+d^2)=(ac\pm bd)^2+(ad\mp bc)^2$$