10x^2-39x-4=0

Solution for 10x^2-39x-4=0 equation:

10x^2-39x-4=0

a = 10; b = -39; c = -4;
Δ = b2-4ac
Δ = -392-4·10·(-4)
Δ = 1681
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1681}=41$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-39)-41}{2*10}=\frac{-2}{20}
=-1/10
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-39)+41}{2*10}=\frac{80}{20}
=4
$