-18x2-6x+4=0

Solution for -18x2-6x+4=0 equation:

-18x^2-6x+4=0

a = -18; b = -6; c = +4;
Δ = b2-4ac
Δ = -62-4·(-18)·4
Δ = 324
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{324}=18$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-6)-18}{2*-18}=\frac{-12}{-36}
=1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-6)+18}{2*-18}=\frac{24}{-36}
=-2/3
$