y^2-81x^2=0

Solution for y^2-81x^2=0 equation:

Simplifying
y2 + -81x2 = 0

Reorder the terms:
-81x2 + y2 = 0

Solving
-81x2 + y2 = 0

Solving for variable 'x'.

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

Add '-1y2' to each side of the equation.
-81x2 + y2 + -1y2 = 0 + -1y2

Combine like terms: y2 + -1y2 = 0
-81x2 + 0 = 0 + -1y2
-81x2 = 0 + -1y2
Remove the zero:
-81x2 = -1y2

Divide each side by '-81'.
x2 = 0.01234567901y2

Simplifying
x2 = 0.01234567901y2

Take the square root of each side:
x = {-0.111111111y, 0.111111111y}