500=9x^2

Solution for 500=9x^2 equation:

500=9x^2

We move all terms to the left:

500-(9x^2)=0

a = -9; b = 0; c = +500;
Δ = b2-4ac
Δ = 02-4·(-9)·500
Δ = 18000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{18000}=\sqrt{3600*5}=\sqrt{3600}*\sqrt{5}=60\sqrt{5}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-60\sqrt{5}}{2*-9}=\frac{0-60\sqrt{5}}{-18}
=-\frac{60\sqrt{5}}{-18}
=-\frac{10\sqrt{5}}{-3}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+60\sqrt{5}}{2*-9}=\frac{0+60\sqrt{5}}{-18}
=\frac{60\sqrt{5}}{-18}
=\frac{10\sqrt{5}}{-3}
$