Expand the expression in the equation
$$\left(- 2 x - 3\right) \left(x - 2\right) = 0$$
We get the quadratic equation
$$- 2 x^{2} + x + 6 = 0$$
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
$$a = -2$$
$$b = 1$$
$$c = 6$$
, then
D = b^2 - 4 * a * c =
(1)^2 - 4 * (-2) * (6) = 49
Because D > 0, then the equation has two roots.
x1 = (-b + sqrt(D)) / (2*a)
x2 = (-b - sqrt(D)) / (2*a)
or
$$x_{1} = - \frac{3}{2}$$
$$x_{2} = 2$$