-5k(k-6)=0

Solution for -5k(k-6)=0 equation:

-5k(k-6)=0

We multiply parentheses

-5k^2+30k=0

a = -5; b = 30; c = 0;
Δ = b2-4ac
Δ = 302-4·(-5)·0
Δ = 900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{900}=30$
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(30)-30}{2*-5}=\frac{-60}{-10}
=+6
$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(30)+30}{2*-5}=\frac{0}{-10}
=0
$