81=a^2

Solution for 81=a^2 equation:

Simplifying
81 = a2

Solving
81 = a2

Solving for variable 'a'.

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

Add '-1a2' to each side of the equation.
81 + -1a2 = a2 + -1a2

Combine like terms: a2 + -1a2 = 0
81 + -1a2 = 0

Add '-81' to each side of the equation.
81 + -81 + -1a2 = 0 + -81

Combine like terms: 81 + -81 = 0
0 + -1a2 = 0 + -81
-1a2 = 0 + -81

Combine like terms: 0 + -81 = -81
-1a2 = -81

Divide each side by '-1'.
a2 = 81

Simplifying
a2 = 81

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