-16m-21=3m^2

Solution for -16m-21=3m^2 equation:

-16m-21=3m^2

We move all terms to the left:

-16m-21-(3m^2)=0

determiningTheFunctionDomain
-3m^2-16m-21=0

a = -3; b = -16; c = -21;
Δ = b2-4ac
Δ = -162-4·(-3)·(-21)
Δ = 4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4}=2$
$m_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-2}{2*-3}=\frac{14}{-6}
=-2+1/3
$
$m_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+2}{2*-3}=\frac{18}{-6}
=-3
$