-5u^2-39u-4=0

Solution for -5u^2-39u-4=0 equation:

-5u^2-39u-4=0

a = -5; b = -39; c = -4;
Δ = b2-4ac
Δ = -392-4·(-5)·(-4)
Δ = 1441
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-39)-\sqrt{1441}}{2*-5}=\frac{39-\sqrt{1441}}{-10}
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-39)+\sqrt{1441}}{2*-5}=\frac{39+\sqrt{1441}}{-10}
$