0=8h^2+12h-396

Solution for 0=8h^2+12h-396 equation:

0=8h^2+12h-396

We move all terms to the left:

0-(8h^2+12h-396)=0

We add all the numbers together, and all the variables

-(8h^2+12h-396)=0

We get rid of parentheses

-8h^2-12h+396=0

a = -8; b = -12; c = +396;
Δ = b2-4ac
Δ = -122-4·(-8)·396
Δ = 12816
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$h_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$h_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{12816}=\sqrt{144*89}=\sqrt{144}*\sqrt{89}=12\sqrt{89}$
$h_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-12\sqrt{89}}{2*-8}=\frac{12-12\sqrt{89}}{-16}
$
$h_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+12\sqrt{89}}{2*-8}=\frac{12+12\sqrt{89}}{-16}
$