P(x)=-9x^2

Solution for P(x)=-9x^2 equation:

(P)=-9P^2

We move all terms to the left:

(P)-(-9P^2)=0

We get rid of parentheses

9P^2+P=0

a = 9; b = 1; c = 0;
Δ = b2-4ac
Δ = 12-4·9·0
Δ = 1
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$P_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$P_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1}=1$
$P_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1)-1}{2*9}=\frac{-2}{18}
=-1/9
$
$P_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+1}{2*9}=\frac{0}{18}
=0
$