-4p^2-12p+9=0

Solution for -4p^2-12p+9=0 equation:

-4p^2-12p+9=0

a = -4; b = -12; c = +9;
Δ = b2-4ac
Δ = -122-4·(-4)·9
Δ = 288
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{288}=\sqrt{144*2}=\sqrt{144}*\sqrt{2}=12\sqrt{2}$
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-12\sqrt{2}}{2*-4}=\frac{12-12\sqrt{2}}{-8}
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+12\sqrt{2}}{2*-4}=\frac{12+12\sqrt{2}}{-8}
$