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x²-64=0 equation

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Numerical solution:

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The solution

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x  - 64 = 0
$$x^{2} - 64 = 0$$
Detail solution
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
$$a = 1$$
$$b = 0$$
$$c = -64$$
, then
D = b^2 - 4 * a * c = 

(0)^2 - 4 * (1) * (-64) = 256

Because D > 0, then the equation has two roots.
x1 = (-b + sqrt(D)) / (2*a)

x2 = (-b - sqrt(D)) / (2*a)

or
$$x_{1} = 8$$
$$x_{2} = -8$$
Vieta's Theorem
it is reduced quadratic equation
$$p x + q + x^{2} = 0$$
where
$$p = \frac{b}{a}$$
$$p = 0$$
$$q = \frac{c}{a}$$
$$q = -64$$
Vieta Formulas
$$x_{1} + x_{2} = - p$$
$$x_{1} x_{2} = q$$
$$x_{1} + x_{2} = 0$$
$$x_{1} x_{2} = -64$$
Sum and product of roots [src]
sum
-8 + 8
$$-8 + 8$$
=
0
$$0$$
product
-8*8
$$- 64$$
=
-64
$$-64$$
-64
Rapid solution [src]
x1 = -8
$$x_{1} = -8$$
x2 = 8
$$x_{2} = 8$$
x2 = 8
Numerical answer [src]
x1 = 8.0
x2 = -8.0
x2 = -8.0