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

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

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

We move all terms to the left:

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

We multiply parentheses

-2m^2-8m-(-2m-6)=0

We get rid of parentheses

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

We add all the numbers together, and all the variables

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

a = -2; b = -6; c = +6;
Δ = b2-4ac
Δ = -62-4·(-2)·6
Δ = 84
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:

$\sqrt{\Delta}=\sqrt{84}=\sqrt{4*21}=\sqrt{4}*\sqrt{21}=2\sqrt{21}$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-6)-2\sqrt{21}}{2*-2}=\frac{6-2\sqrt{21}}{-4}
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6)+2\sqrt{21}}{2*-2}=\frac{6+2\sqrt{21}}{-4}
$