64.1=.5t^2+1.4t+66.5

Solution for 64.1=.5t^2+1.4t+66.5 equation:

Simplifying
64.1 = 0.5t2 + 1.4t + 66.5

Reorder the terms:
64.1 = 66.5 + 1.4t + 0.5t2

Solving
64.1 = 66.5 + 1.4t + 0.5t2

Solving for variable 't'.

Combine like terms: 64.1 + -66.5 = -2.4
-2.4 + -1.4t + -0.5t2 = 66.5 + 1.4t + 0.5t2 + -66.5 + -1.4t + -0.5t2

Reorder the terms:
-2.4 + -1.4t + -0.5t2 = 66.5 + -66.5 + 1.4t + -1.4t + 0.5t2 + -0.5t2

Combine like terms: 66.5 + -66.5 = 0.0
-2.4 + -1.4t + -0.5t2 = 0.0 + 1.4t + -1.4t + 0.5t2 + -0.5t2
-2.4 + -1.4t + -0.5t2 = 1.4t + -1.4t + 0.5t2 + -0.5t2

Combine like terms: 1.4t + -1.4t = 0.0
-2.4 + -1.4t + -0.5t2 = 0.0 + 0.5t2 + -0.5t2
-2.4 + -1.4t + -0.5t2 = 0.5t2 + -0.5t2

Combine like terms: 0.5t2 + -0.5t2 = 0.0
-2.4 + -1.4t + -0.5t2 = 0.0

Begin completing the square.  Divide all terms by
-0.5 the coefficient of the squared term: 

Divide each side by '-0.5'.
4.8 + 2.8t + t2 = 0

Move the constant term to the right:

Add '-4.8' to each side of the equation.
4.8 + 2.8t + -4.8 + t2 = 0 + -4.8

Reorder the terms:
4.8 + -4.8 + 2.8t + t2 = 0 + -4.8

Combine like terms: 4.8 + -4.8 = 0.0
0.0 + 2.8t + t2 = 0 + -4.8
2.8t + t2 = 0 + -4.8

Combine like terms: 0 + -4.8 = -4.8
2.8t + t2 = -4.8

The t term is 2.8t.  Take half its coefficient (1.4).
Square it (1.96) and add it to both sides.

Add '1.96' to each side of the equation.
2.8t + 1.96 + t2 = -4.8 + 1.96

Reorder the terms:
1.96 + 2.8t + t2 = -4.8 + 1.96

Combine like terms: -4.8 + 1.96 = -2.84
1.96 + 2.8t + t2 = -2.84

Factor a perfect square on the left side:
(t + 1.4)(t + 1.4) = -2.84

Can't calculate square root of the right side.

The solution to this equation could not be determined.