jika [tex] {x}^{2} + \frac{1}{ {x}^{2} } = 66[/tex] maka nilai [tex]x - \frac{1}{x} [/tex] adalah

x² + 1/x² = 66
(x - 1/x)² + 2 = 66
(x - 1/x)² = 64
x - 1/x = ± 8

Jadi,
x - 1/x = 8 atau x - 1/x = -8

[tex] {x}^{2} + \frac{1}{ {x}^{2} } = {( x - \frac{1}{x} )}^{2} + 2 \\ {(x - \frac{1}{x}) }^{2} = 64 \\ {(x - \frac{1}{x}) } = 8[/tex]

x= +/-8