x2-8x-1720=0

Solution for x2-8x-1720=0 equation:

x2-8x-1720=0

We add all the numbers together, and all the variables

x^2-8x-1720=0

a = 1; b = -8; c = -1720;
Δ = b2-4ac
Δ = -82-4·1·(-1720)
Δ = 6944
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:

$\sqrt{\Delta}=\sqrt{6944}=\sqrt{16*434}=\sqrt{16}*\sqrt{434}=4\sqrt{434}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-4\sqrt{434}}{2*1}=\frac{8-4\sqrt{434}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+4\sqrt{434}}{2*1}=\frac{8+4\sqrt{434}}{2}
$