(x² + y²)/xy = 5 হলে (x²/y²) + (y²/x²) এর মান কত?

দেয়া আছে
(x² + y²)/xy = 5
x²/xy + y²/xy = 5
(x/y) + (y/x) = 5

(x²/y²) + (y²/x²) = (x/y)² + (y/x)²
= {(x/y) + (y/x)}² - 2.(x/y) . (y/x)
= 5² - 2
= 25 - 2
= 23