-18p^2-21p+15=0

Solution for -18p^2-21p+15=0 equation:

-18p^2-21p+15=0

a = -18; b = -21; c = +15;
Δ = b2-4ac
Δ = -212-4·(-18)·15
Δ = 1521
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1521}=39$
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-21)-39}{2*-18}=\frac{-18}{-36}
=1/2
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-21)+39}{2*-18}=\frac{60}{-36}
=-1+2/3
$