-81x^2+4=0

Solution for -81x^2+4=0 equation:

Simplifying
-81x2 + 4 = 0

Reorder the terms:
4 + -81x2 = 0

Solving
4 + -81x2 = 0

Solving for variable 'x'.

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

Add '-4' to each side of the equation.
4 + -4 + -81x2 = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -81x2 = 0 + -4
-81x2 = 0 + -4

Combine like terms: 0 + -4 = -4
-81x2 = -4

Divide each side by '-81'.
x2 = 0.04938271605

Simplifying
x2 = 0.04938271605

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