If $x^{4} + x^{2} y^{2} + y^{4} = 273$ and $x^{2} - xy + y^{2} = 13$, then the value of xy is :
Answer & explanation
Correct answer: option 1
x4 + x2y2 + y4 = (x2 – xy + y2) (x2 + xy + y2)
If $x^{4} + x^{2} y^{2} + y^{4} = 273$
$x^{2} - xy + y^{2} = 13$ ----(A)
Then, $x^{2} + xy + y^{2} = \frac{273}{13}$ = 21-----(B)
From equation A and B
The value of xy = 4