81p^2-5=-1

Solution for 81p^2-5=-1 equation:

81p^2-5=-1

We move all terms to the left:

81p^2-5-(-1)=0

We add all the numbers together, and all the variables

81p^2-4=0

a = 81; b = 0; c = -4;
Δ = b2-4ac
Δ = 02-4·81·(-4)
Δ = 1296
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1296}=36$
$p_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-36}{2*81}=\frac{-36}{162}
=-2/9
$
$p_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+36}{2*81}=\frac{36}{162}
=2/9
$