81v^2-u^2=

Solution for 81v^2-u^2= equation:

Simplifying
81v2 + -1u2 = 0

Reorder the terms:
-1u2 + 81v2 = 0

Solving
-1u2 + 81v2 = 0

Solving for variable 'u'.

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

Add '-81v2' to each side of the equation.
-1u2 + 81v2 + -81v2 = 0 + -81v2

Combine like terms: 81v2 + -81v2 = 0
-1u2 + 0 = 0 + -81v2
-1u2 = 0 + -81v2
Remove the zero:
-1u2 = -81v2

Divide each side by '-1'.
u2 = 81v2

Simplifying
u2 = 81v2

Take the square root of each side:
u = {-9v, 9v}