5x^2-160x-20=0

Solution for 5x^2-160x-20=0 equation:

5x^2-160x-20=0

a = 5; b = -160; c = -20;
Δ = b2-4ac
Δ = -1602-4·5·(-20)
Δ = 26000
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:

$\sqrt{\Delta}=\sqrt{26000}=\sqrt{400*65}=\sqrt{400}*\sqrt{65}=20\sqrt{65}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-160)-20\sqrt{65}}{2*5}=\frac{160-20\sqrt{65}}{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-160)+20\sqrt{65}}{2*5}=\frac{160+20\sqrt{65}}{10}
$