4k^2-16k-8=0

Solution for 4k^2-16k-8=0 equation:

4k^2-16k-8=0

a = 4; b = -16; c = -8;
Δ = b2-4ac
Δ = -162-4·4·(-8)
Δ = 384
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{384}=\sqrt{64*6}=\sqrt{64}*\sqrt{6}=8\sqrt{6}$
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-8\sqrt{6}}{2*4}=\frac{16-8\sqrt{6}}{8}
$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+8\sqrt{6}}{2*4}=\frac{16+8\sqrt{6}}{8}
$