[tex]\mathfrak{\huge{\orange{\underline{\underline{AnSwEr:-}}}}}[/tex]
Actually Welcome to the Concept of the quadratic equations.
Since, as the question told,
=>
[tex] \frac{ {x}^{2} }{3} - 3 = 0[/tex]
hence now solving we get as,
[tex] \frac{ {x}^{2} }{3 } = 3 [/tex]
now, we get as,
[tex] {x}^{2} = 9[/tex]
now, then
[tex] \sqrt{ {x}^{2} } = \sqrt{9} [/tex]
so finally, positive value of x is 3