729=x2

Solution for 729=x2 equation:

729=x2

We move all terms to the left:

729-(x2)=0

We add all the numbers together, and all the variables

-1x^2+729=0

a = -1; b = 0; c = +729;
Δ = b2-4ac
Δ = 02-4·(-1)·729
Δ = 2916
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2916}=54$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-54}{2*-1}=\frac{-54}{-2}
=+27
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+54}{2*-1}=\frac{54}{-2}
=-27
$