C=256+16w-2w2

Solution for C=256+16w-2w2 equation:

=256+16C-2C^2

We move all terms to the left:

-(256+16C-2C^2)=0

We get rid of parentheses

2C^2-16C-256=0

a = 2; b = -16; c = -256;
Δ = b2-4ac
Δ = -162-4·2·(-256)
Δ = 2304
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$C_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$C_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2304}=48$
$C_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-48}{2*2}=\frac{-32}{4}
=-8
$
$C_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+48}{2*2}=\frac{64}{4}
=16
$