256+16x+x^2+144-24x+4x^2=400

Solution for 256+16x+x^2+144-24x+4x^2=400 equation:

256+16x+x^2+144-24x+4x^2=400

We move all terms to the left:

256+16x+x^2+144-24x+4x^2-(400)=0

We add all the numbers together, and all the variables

5x^2-8x=0

a = 5; b = -8; c = 0;
Δ = b2-4ac
Δ = -82-4·5·0
Δ = 64
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{64}=8$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-8}{2*5}=\frac{0}{10}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+8}{2*5}=\frac{16}{10}
=1+3/5
$