(4.9)*t^2+(98)*t+686=0

Solution for (4.9)*t^2+(98)*t+686=0 equation:

Simplifying
(4.9) * t2 + (98) * t + 686 = 0

Reorder the terms:
686 + 98t + 4.9t2 = 0

Solving
686 + 98t + 4.9t2 = 0

Solving for variable 't'.

Begin completing the square.  Divide all terms by
4.9 the coefficient of the squared term: 

Divide each side by '4.9'.
140 + 20t + t2 = 0

Move the constant term to the right:

Add '-140' to each side of the equation.
140 + 20t + -140 + t2 = 0 + -140

Reorder the terms:
140 + -140 + 20t + t2 = 0 + -140

Combine like terms: 140 + -140 = 0
0 + 20t + t2 = 0 + -140
20t + t2 = 0 + -140

Combine like terms: 0 + -140 = -140
20t + t2 = -140

The t term is 20t.  Take half its coefficient (10).
Square it (100) and add it to both sides.

Add '100' to each side of the equation.
20t + 100 + t2 = -140 + 100

Reorder the terms:
100 + 20t + t2 = -140 + 100

Combine like terms: -140 + 100 = -40
100 + 20t + t2 = -40

Factor a perfect square on the left side:
(t + 10)(t + 10) = -40

Can't calculate square root of the right side.

The solution to this equation could not be determined.