-10x^2-5x+15=0

Solution for -10x^2-5x+15=0 equation:

-10x^2-5x+15=0

a = -10; b = -5; c = +15;
Δ = b2-4ac
Δ = -52-4·(-10)·15
Δ = 625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{625}=25$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5)-25}{2*-10}=\frac{-20}{-20}
=1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+25}{2*-10}=\frac{30}{-20}
=-1+1/2
$