810000=x2*10

Solution for 810000=x2*10 equation:

810000=x2*10

We move all terms to the left:

810000-(x2*10)=0

We add all the numbers together, and all the variables

-(+x2*10)+810000=0

We get rid of parentheses

-x2*10+810000=0

Wy multiply elements

-10x^2+810000=0

a = -10; b = 0; c = +810000;
Δ = b2-4ac
Δ = 02-4·(-10)·810000
Δ = 32400000
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:

$\sqrt{\Delta}=\sqrt{32400000}=\sqrt{3240000*10}=\sqrt{3240000}*\sqrt{10}=1800\sqrt{10}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-1800\sqrt{10}}{2*-10}=\frac{0-1800\sqrt{10}}{-20}
=-\frac{1800\sqrt{10}}{-20}
=-\frac{90\sqrt{10}}{-1}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+1800\sqrt{10}}{2*-10}=\frac{0+1800\sqrt{10}}{-20}
=\frac{1800\sqrt{10}}{-20}
=\frac{90\sqrt{10}}{-1}
$