x*0.15x=2500000

Solution for x*0.15x=2500000 equation:

x*0.15x=2500000

We move all terms to the left:

x*0.15x-(2500000)=0

Wy multiply elements

0x^2-2500000=0

We add all the numbers together, and all the variables

x^2-2500000=0

a = 1; b = 0; c = -2500000;
Δ = b2-4ac
Δ = 02-4·1·(-2500000)
Δ = 10000000
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:

$\sqrt{\Delta}=\sqrt{10000000}=\sqrt{1000000*10}=\sqrt{1000000}*\sqrt{10}=1000\sqrt{10}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-1000\sqrt{10}}{2*1}=\frac{0-1000\sqrt{10}}{2}
=-\frac{1000\sqrt{10}}{2}
=-500\sqrt{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+1000\sqrt{10}}{2*1}=\frac{0+1000\sqrt{10}}{2}
=\frac{1000\sqrt{10}}{2}
=500\sqrt{10}
$