1=0*t+0.5*9.8*t*t

Solution for 1=0*t+0.5*9.8*t*t equation:

Simplifying
1 = 0t + 0.5 * 9.8t * t

Anything times zero is zero.
1 = 0t + 0.5 * 9.8t * t

Multiply 0.5 * 9.8
1 = 0 + 4.9t * t

Multiply t * t
1 = 0 + 4.9t2
Remove the zero:
1 = 4.9t2

Solving
1 = 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.
1 + -4.9t2 = 4.9t2 + -4.9t2

Combine like terms: 4.9t2 + -4.9t2 = 0.0
1 + -4.9t2 = 0.0

Add '-1' to each side of the equation.
1 + -1 + -4.9t2 = 0.0 + -1

Combine like terms: 1 + -1 = 0
0 + -4.9t2 = 0.0 + -1
-4.9t2 = 0.0 + -1

Combine like terms: 0.0 + -1 = -1
-4.9t2 = -1

Divide each side by '-4.9'.
t2 = 0.2040816327

Simplifying
t2 = 0.2040816327

Take the square root of each side:
t = {-0.451753952, 0.451753952}