182368.2=r^2-4r

Solution for 182368.2=r^2-4r equation:

182368.2=r^2-4r

We move all terms to the left:

182368.2-(r^2-4r)=0

We get rid of parentheses

-r^2+4r+182368.2=0

We add all the numbers together, and all the variables

-1r^2+4r+182368.2=0

a = -1; b = 4; c = +182368.2;
Δ = b2-4ac
Δ = 42-4·(-1)·182368.2
Δ = 729488.8
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-\sqrt{729488.8}}{2*-1}=\frac{-4-\sqrt{729488.8}}{-2}
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+\sqrt{729488.8}}{2*-1}=\frac{-4+\sqrt{729488.8}}{-2}
$