-6(k+5)(k+2)=0

Solution for -6(k+5)(k+2)=0 equation:

-6(k+5)(k+2)=0

We multiply parentheses ..

-6(+k^2+2k+5k+10)=0

We multiply parentheses

-6k^2-12k-30k-60=0

We add all the numbers together, and all the variables

-6k^2-42k-60=0

a = -6; b = -42; c = -60;
Δ = b2-4ac
Δ = -422-4·(-6)·(-60)
Δ = 324
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{324}=18$
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-42)-18}{2*-6}=\frac{24}{-12}
=-2
$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-42)+18}{2*-6}=\frac{60}{-12}
=-5
$