-4c(-c-16)=-4c-16

Solution for -4c(-c-16)=-4c-16 equation:

-4c(-c-16)=-4c-16

We move all terms to the left:

-4c(-c-16)-(-4c-16)=0

We add all the numbers together, and all the variables

-4c(-1c-16)-(-4c-16)=0

We multiply parentheses

4c^2+64c-(-4c-16)=0

We get rid of parentheses

4c^2+64c+4c+16=0

We add all the numbers together, and all the variables

4c^2+68c+16=0

a = 4; b = 68; c = +16;
Δ = b2-4ac
Δ = 682-4·4·16
Δ = 4368
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{4368}=\sqrt{16*273}=\sqrt{16}*\sqrt{273}=4\sqrt{273}$
$c_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(68)-4\sqrt{273}}{2*4}=\frac{-68-4\sqrt{273}}{8}
$
$c_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(68)+4\sqrt{273}}{2*4}=\frac{-68+4\sqrt{273}}{8}
$