0=0.81x^2-50

Solution for 0=0.81x^2-50 equation:

Simplifying
0 = 0.81x2 + -50

Reorder the terms:
0 = -50 + 0.81x2

Solving
0 = -50 + 0.81x2

Solving for variable 'x'.

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

Add '-0.81x2' to each side of the equation.
0 + -0.81x2 = -50 + 0.81x2 + -0.81x2
Remove the zero:
-0.81x2 = -50 + 0.81x2 + -0.81x2

Combine like terms: 0.81x2 + -0.81x2 = 0.00
-0.81x2 = -50 + 0.00
-0.81x2 = -50

Divide each side by '-0.81'.
x2 = 61.72839506

Simplifying
x2 = 61.72839506

Take the square root of each side:
x = {-7.856742013, 7.856742013}