0=6x^2+18x-168

Solution for 0=6x^2+18x-168 equation:

0=6x^2+18x-168

We move all terms to the left:

0-(6x^2+18x-168)=0

We add all the numbers together, and all the variables

-(6x^2+18x-168)=0

We get rid of parentheses

-6x^2-18x+168=0

a = -6; b = -18; c = +168;
Δ = b2-4ac
Δ = -182-4·(-6)·168
Δ = 4356
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4356}=66$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-18)-66}{2*-6}=\frac{-48}{-12}
=+4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-18)+66}{2*-6}=\frac{84}{-12}
=-7
$