x^2-13^2-8=0

Solution for x^2-13^2-8=0 equation:

x^2-13^2-8=0

We add all the numbers together, and all the variables

x^2-177=0

a = 1; b = 0; c = -177;
Δ = b2-4ac
Δ = 02-4·1·(-177)
Δ = 708
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:

$\sqrt{\Delta}=\sqrt{708}=\sqrt{4*177}=\sqrt{4}*\sqrt{177}=2\sqrt{177}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-2\sqrt{177}}{2*1}=\frac{0-2\sqrt{177}}{2}
=-\frac{2\sqrt{177}}{2}
=-\sqrt{177}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+2\sqrt{177}}{2*1}=\frac{0+2\sqrt{177}}{2}
=\frac{2\sqrt{177}}{2}
=\sqrt{177}
$