0=x^2+72x-3120

Solution for 0=x^2+72x-3120 equation:

0=x^2+72x-3120

We move all terms to the left:

0-(x^2+72x-3120)=0

We add all the numbers together, and all the variables

-(x^2+72x-3120)=0

We get rid of parentheses

-x^2-72x+3120=0

We add all the numbers together, and all the variables

-1x^2-72x+3120=0

a = -1; b = -72; c = +3120;
Δ = b2-4ac
Δ = -722-4·(-1)·3120
Δ = 17664
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:

$\sqrt{\Delta}=\sqrt{17664}=\sqrt{256*69}=\sqrt{256}*\sqrt{69}=16\sqrt{69}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-72)-16\sqrt{69}}{2*-1}=\frac{72-16\sqrt{69}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-72)+16\sqrt{69}}{2*-1}=\frac{72+16\sqrt{69}}{-2}
$