-18x^2-15x+12=0

Solution for -18x^2-15x+12=0 equation:

-18x^2-15x+12=0

a = -18; b = -15; c = +12;
Δ = b2-4ac
Δ = -152-4·(-18)·12
Δ = 1089
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1089}=33$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15)-33}{2*-18}=\frac{-18}{-36}
=1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+33}{2*-18}=\frac{48}{-36}
=-1+1/3
$