k(5k-12)=0

Solution for k(5k-12)=0 equation:

k(5k-12)=0

We multiply parentheses

5k^2-12k=0

a = 5; b = -12; c = 0;
Δ = b2-4ac
Δ = -122-4·5·0
Δ = 144
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{144}=12$
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-12}{2*5}=\frac{0}{10}
=0
$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+12}{2*5}=\frac{24}{10}
=2+2/5
$