81k^2-4=0

Solution for 81k^2-4=0 equation:

Simplifying
81k2 + -4 = 0

Reorder the terms:
-4 + 81k2 = 0

Solving
-4 + 81k2 = 0

Solving for variable 'k'.

Move all terms containing k to the left, all other terms to the right.

Add '4' to each side of the equation.
-4 + 4 + 81k2 = 0 + 4

Combine like terms: -4 + 4 = 0
0 + 81k2 = 0 + 4
81k2 = 0 + 4

Combine like terms: 0 + 4 = 4
81k2 = 4

Divide each side by '81'.
k2 = 0.04938271605

Simplifying
k2 = 0.04938271605

Take the square root of each side:
k = {-0.222222222, 0.222222222}