0=3x^2+9x-324

Solution for 0=3x^2+9x-324 equation:

0=3x^2+9x-324

We move all terms to the left:

0-(3x^2+9x-324)=0

We add all the numbers together, and all the variables

-(3x^2+9x-324)=0

We get rid of parentheses

-3x^2-9x+324=0

a = -3; b = -9; c = +324;
Δ = b2-4ac
Δ = -92-4·(-3)·324
Δ = 3969
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3969}=63$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-9)-63}{2*-3}=\frac{-54}{-6}
=+9
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+63}{2*-3}=\frac{72}{-6}
=-12
$