6m(m+5)=20

Solution for 6m(m+5)=20 equation:

6m(m+5)=20

We move all terms to the left:

6m(m+5)-(20)=0

We multiply parentheses

6m^2+30m-20=0

a = 6; b = 30; c = -20;
Δ = b2-4ac
Δ = 302-4·6·(-20)
Δ = 1380
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1380}=\sqrt{4*345}=\sqrt{4}*\sqrt{345}=2\sqrt{345}$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(30)-2\sqrt{345}}{2*6}=\frac{-30-2\sqrt{345}}{12}
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(30)+2\sqrt{345}}{2*6}=\frac{-30+2\sqrt{345}}{12}
$