80=.5*9.8t^2

Solution for 80=.5*9.8t^2 equation:

Simplifying
80 = 0.5 * 9.8t2

Multiply 0.5 * 9.8
80 = 4.9t2

Solving
80 = 4.9t2

Solving for variable 't'.

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

Add '-4.9t2' to each side of the equation.
80 + -4.9t2 = 4.9t2 + -4.9t2

Combine like terms: 4.9t2 + -4.9t2 = 0.0
80 + -4.9t2 = 0.0

Add '-80' to each side of the equation.
80 + -80 + -4.9t2 = 0.0 + -80

Combine like terms: 80 + -80 = 0
0 + -4.9t2 = 0.0 + -80
-4.9t2 = 0.0 + -80

Combine like terms: 0.0 + -80 = -80
-4.9t2 = -80

Divide each side by '-4.9'.
t2 = 16.32653061

Simplifying
t2 = 16.32653061

Take the square root of each side:
t = {-4.040610178, 4.040610178}