-4k=4k(k-8)

Solution for -4k=4k(k-8) equation:

-4k=4k(k-8)

We move all terms to the left:

-4k-(4k(k-8))=0


We calculate terms in parentheses: -(4k(k-8)), so:

4k(k-8)

We multiply parentheses

4k^2-32k

Back to the equation:

-(4k^2-32k)


We get rid of parentheses

-4k^2-4k+32k=0

We add all the numbers together, and all the variables

-4k^2+28k=0

a = -4; b = 28; c = 0;
Δ = b2-4ac
Δ = 282-4·(-4)·0
Δ = 784
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{784}=28$
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(28)-28}{2*-4}=\frac{-56}{-8}
=+7
$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(28)+28}{2*-4}=\frac{0}{-8}
=0
$