How can I transform the product 365(15^2+16^2) into sum of two squares???
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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 07:48
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Any of them. I need the method. – Avirup Biswas Nov 22 '16 at 07:50
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See How do you prove that a prime is the sum of two squares iff it is congruent to 1 mod 4?
As $365=5\cdot73$
$5=1^2+2^2$
$73=8^2+3^2$
Use Brahmagupta-Fibonacci Identity $$(a^2+b^2)(c^2+d^2)=(ac\pm bd)^2+(ad\mp bc)^2$$
lab bhattacharjee
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