81a2=1

Solution for 81a2=1 equation:

81a^2=1

We move all terms to the left:

81a^2-(1)=0

a = 81; b = 0; c = -1;
Δ = b2-4ac
Δ = 02-4·81·(-1)
Δ = 324
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{324}=18$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-18}{2*81}=\frac{-18}{162}
=-1/9
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+18}{2*81}=\frac{18}{162}
=1/9
$