-9x^2-15x-6=0

Solution for -9x^2-15x-6=0 equation:

-9x^2-15x-6=0

a = -9; b = -15; c = -6;
Δ = b2-4ac
Δ = -152-4·(-9)·(-6)
Δ = 9
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9}=3$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15)-3}{2*-9}=\frac{12}{-18}
=-2/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+3}{2*-9}=\frac{18}{-18}
=-1
$