5x^2-40x-60=0

Solution for 5x^2-40x-60=0 equation:

5x^2-40x-60=0

a = 5; b = -40; c = -60;
Δ = b2-4ac
Δ = -402-4·5·(-60)
Δ = 2800
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:

$\sqrt{\Delta}=\sqrt{2800}=\sqrt{400*7}=\sqrt{400}*\sqrt{7}=20\sqrt{7}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-40)-20\sqrt{7}}{2*5}=\frac{40-20\sqrt{7}}{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-40)+20\sqrt{7}}{2*5}=\frac{40+20\sqrt{7}}{10}
$