-10x^2-31x-15=0

Solution for -10x^2-31x-15=0 equation:

-10x^2-31x-15=0

a = -10; b = -31; c = -15;
Δ = b2-4ac
Δ = -312-4·(-10)·(-15)
Δ = 361
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{361}=19$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-31)-19}{2*-10}=\frac{12}{-20}
=-3/5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-31)+19}{2*-10}=\frac{50}{-20}
=-2+1/2
$