3k(k+10)=10

Solution for 3k(k+10)=10 equation:

3k(k+10)=10

We move all terms to the left:

3k(k+10)-(10)=0

We multiply parentheses

3k^2+30k-10=0

a = 3; b = 30; c = -10;
Δ = b2-4ac
Δ = 302-4·3·(-10)
Δ = 1020
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1020}=\sqrt{4*255}=\sqrt{4}*\sqrt{255}=2\sqrt{255}$
$k_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(30)-2\sqrt{255}}{2*3}=\frac{-30-2\sqrt{255}}{6}
$
$k_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(30)+2\sqrt{255}}{2*3}=\frac{-30+2\sqrt{255}}{6}
$