81v^2-61=0

Solution for 81v^2-61=0 equation:

Simplifying
81v2 + -61 = 0

Reorder the terms:
-61 + 81v2 = 0

Solving
-61 + 81v2 = 0

Solving for variable 'v'.

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

Add '61' to each side of the equation.
-61 + 61 + 81v2 = 0 + 61

Combine like terms: -61 + 61 = 0
0 + 81v2 = 0 + 61
81v2 = 0 + 61

Combine like terms: 0 + 61 = 61
81v2 = 61

Divide each side by '81'.
v2 = 0.7530864198

Simplifying
v2 = 0.7530864198

Take the square root of each side:
v = {-0.86780552, 0.86780552}