-3y^2-12y-9=0

Solution for -3y^2-12y-9=0 equation:

-3y^2-12y-9=0

a = -3; b = -12; c = -9;
Δ = b2-4ac
Δ = -122-4·(-3)·(-9)
Δ = 36
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{36}=6$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-6}{2*-3}=\frac{6}{-6}
=-1
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+6}{2*-3}=\frac{18}{-6}
=-3
$