100=.81t^2

Solution for 100=.81t^2 equation:

Simplifying
100 = 0.81t2

Solving
100 = 0.81t2

Solving for variable 't'.

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

Add '-0.81t2' to each side of the equation.
100 + -0.81t2 = 0.81t2 + -0.81t2

Combine like terms: 0.81t2 + -0.81t2 = 0.00
100 + -0.81t2 = 0.00

Add '-100' to each side of the equation.
100 + -100 + -0.81t2 = 0.00 + -100

Combine like terms: 100 + -100 = 0
0 + -0.81t2 = 0.00 + -100
-0.81t2 = 0.00 + -100

Combine like terms: 0.00 + -100 = -100
-0.81t2 = -100

Divide each side by '-0.81'.
t2 = 123.4567901

Simplifying
t2 = 123.4567901

Take the square root of each side:
t = {-11.11111111, 11.11111111}