-14=-3x^2-18x

Solution for -14=-3x^2-18x equation:

-14=-3x^2-18x

We move all terms to the left:

-14-(-3x^2-18x)=0

We get rid of parentheses

3x^2+18x-14=0

a = 3; b = 18; c = -14;
Δ = b2-4ac
Δ = 182-4·3·(-14)
Δ = 492
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{492}=\sqrt{4*123}=\sqrt{4}*\sqrt{123}=2\sqrt{123}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-2\sqrt{123}}{2*3}=\frac{-18-2\sqrt{123}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+2\sqrt{123}}{2*3}=\frac{-18+2\sqrt{123}}{6}
$