10x^2-14x-20=0

Solution for 10x^2-14x-20=0 equation:

10x^2-14x-20=0

a = 10; b = -14; c = -20;
Δ = b2-4ac
Δ = -142-4·10·(-20)
Δ = 996
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:

$\sqrt{\Delta}=\sqrt{996}=\sqrt{4*249}=\sqrt{4}*\sqrt{249}=2\sqrt{249}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-14)-2\sqrt{249}}{2*10}=\frac{14-2\sqrt{249}}{20}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+2\sqrt{249}}{2*10}=\frac{14+2\sqrt{249}}{20}
$