Strange
Number Theory
Level
4
Suppose \(x\) and \(y\) are real numbers such that \(x^2\) and \(y^2\) are positive integers.
Find the maximum value of \(x^2-xy\) if \(\left(3x^2-y^2\right)^2+\left(x^2+y^2\right)^2=72\).
This is a part of the Set.
by
Khang Nguyen Thanh