(-4k+8)(5k-2)=0

Solution for (-4k+8)(5k-2)=0 equation:

(-4k+8)(5k-2)=0

We multiply parentheses ..

(-20k^2+8k+40k-16)=0

We get rid of parentheses

-20k^2+8k+40k-16=0

We add all the numbers together, and all the variables

-20k^2+48k-16=0

a = -20; b = 48; c = -16;
Δ = b2-4ac
Δ = 482-4·(-20)·(-16)
Δ = 1024
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1024}=32$
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(48)-32}{2*-20}=\frac{-80}{-40}
=+2
$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(48)+32}{2*-20}=\frac{-16}{-40}
=2/5
$