Given the equation:
$$\left(\frac{1}{x^{2}} + \frac{2}{x}\right) - 3 = 0$$
Multiply the equation sides by the denominators:
x^2
we get:
$$x^{2} \left(\left(\frac{1}{x^{2}} + \frac{2}{x}\right) - 3\right) = 0$$
$$- 3 x^{2} + 2 x + 1 = 0$$
This equation is of the form
a*x^2 + b*x + c = 0
A quadratic equation can be solved
using the discriminant.
The roots of the quadratic equation:
$$x_{1} = \frac{\sqrt{D} - b}{2 a}$$
$$x_{2} = \frac{- \sqrt{D} - b}{2 a}$$
where D = b^2 - 4*a*c - it is the discriminant.
Because
$$a = -3$$
$$b = 2$$
$$c = 1$$
, then
D = b^2 - 4 * a * c =
(2)^2 - 4 * (-3) * (1) = 16
Because D > 0, then the equation has two roots.
x1 = (-b + sqrt(D)) / (2*a)
x2 = (-b - sqrt(D)) / (2*a)
or
$$x_{1} = - \frac{1}{3}$$
$$x_{2} = 1$$