Question

The sum of the square of a number and one, divided by the difference of 1 from the square gives 221
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220

What is the number?

Answer 1

[tex] x^{2} +1/ x^{2} -1=221/220 [/tex]
$220 x^{2}+220=221 x^{2} +221$
$221 x^{2} -220 x^{2} =220+221$
$x^{2} =441$
$x^{2} =21 ^{2}$
[tex]x=21 [/tex]