x=0.4x^2+360x

Solution for x=0.4x^2+360x equation:

x=0.4x^2+360x

We move all terms to the left:

x-(0.4x^2+360x)=0

We get rid of parentheses

-0.4x^2+x-360x=0

We add all the numbers together, and all the variables

-0.4x^2-359x=0

a = -0.4; b = -359; c = 0;
Δ = b2-4ac
Δ = -3592-4·(-0.4)·0
Δ = 128881
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{128881}=359$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-359)-359}{2*-0.4}=\frac{0}{-0.8}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-359)+359}{2*-0.4}=\frac{718}{-0.8}
=-897+0.39999999999998/0.8
$