6m-2m(m+4)=-28

Solution for 6m-2m(m+4)=-28 equation:

6m-2m(m+4)=-28

We move all terms to the left:

6m-2m(m+4)-(-28)=0

We add all the numbers together, and all the variables

6m-2m(m+4)+28=0

We multiply parentheses

-2m^2+6m-8m+28=0

We add all the numbers together, and all the variables

-2m^2-2m+28=0

a = -2; b = -2; c = +28;
Δ = b2-4ac
Δ = -22-4·(-2)·28
Δ = 228
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:

$\sqrt{\Delta}=\sqrt{228}=\sqrt{4*57}=\sqrt{4}*\sqrt{57}=2\sqrt{57}$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-2\sqrt{57}}{2*-2}=\frac{2-2\sqrt{57}}{-4}
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+2\sqrt{57}}{2*-2}=\frac{2+2\sqrt{57}}{-4}
$