P=0.032n2+5.3n-67400

Solution for P=0.032n2+5.3n-67400 equation:

=0.032P^2+5.3P-67400

We move all terms to the left:

-(0.032P^2+5.3P-67400)=0

We get rid of parentheses

-0.032P^2-5.3P+67400=0

a = -0.032; b = -5.3; c = +67400;
Δ = b2-4ac
Δ = -5.32-4·(-0.032)·67400
Δ = 8655.29
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$P_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$P_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$P_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5.3)-\sqrt{8655.29}}{2*-0.032}=\frac{5.3-\sqrt{8655.29}}{-0.064}
$
$P_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5.3)+\sqrt{8655.29}}{2*-0.032}=\frac{5.3+\sqrt{8655.29}}{-0.064}
$