400000=x^2

Solution for 400000=x^2 equation:

400000=x^2

We move all terms to the left:

400000-(x^2)=0

We add all the numbers together, and all the variables

-1x^2+400000=0

a = -1; b = 0; c = +400000;
Δ = b2-4ac
Δ = 02-4·(-1)·400000
Δ = 1600000
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:

$\sqrt{\Delta}=\sqrt{1600000}=\sqrt{160000*10}=\sqrt{160000}*\sqrt{10}=400\sqrt{10}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-400\sqrt{10}}{2*-1}=\frac{0-400\sqrt{10}}{-2}
=-\frac{400\sqrt{10}}{-2}
=-\frac{200\sqrt{10}}{-1}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+400\sqrt{10}}{2*-1}=\frac{0+400\sqrt{10}}{-2}
=\frac{400\sqrt{10}}{-2}
=\frac{200\sqrt{10}}{-1}
$