3x^2+6x-18=156

Solution for 3x^2+6x-18=156 equation:

3x^2+6x-18=156

We move all terms to the left:

3x^2+6x-18-(156)=0

We add all the numbers together, and all the variables

3x^2+6x-174=0

a = 3; b = 6; c = -174;
Δ = b2-4ac
Δ = 62-4·3·(-174)
Δ = 2124
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:

$\sqrt{\Delta}=\sqrt{2124}=\sqrt{36*59}=\sqrt{36}*\sqrt{59}=6\sqrt{59}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-6\sqrt{59}}{2*3}=\frac{-6-6\sqrt{59}}{6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+6\sqrt{59}}{2*3}=\frac{-6+6\sqrt{59}}{6}
$