-5t^2+10t+65=0

Solution for -5t^2+10t+65=0 equation:

Simplifying
-5t2 + 10t + 65 = 0

Reorder the terms:
65 + 10t + -5t2 = 0

Solving
65 + 10t + -5t2 = 0

Solving for variable 't'.

Factor out the Greatest Common Factor (GCF), '5'.
5(13 + 2t + -1t2) = 0

Ignore the factor 5.
Subproblem 1
Set the factor '(13 + 2t + -1t2)' equal to zero and attempt to solve:

Simplifying
13 + 2t + -1t2 = 0

Solving
13 + 2t + -1t2 = 0

Begin completing the square.  Divide all terms by
-1 the coefficient of the squared term: 

Divide each side by '-1'.
-13 + -2t + t2 = 0

Move the constant term to the right:

Add '13' to each side of the equation.
-13 + -2t + 13 + t2 = 0 + 13

Reorder the terms:
-13 + 13 + -2t + t2 = 0 + 13

Combine like terms: -13 + 13 = 0
0 + -2t + t2 = 0 + 13
-2t + t2 = 0 + 13

Combine like terms: 0 + 13 = 13
-2t + t2 = 13

The t term is -2t.  Take half its coefficient (-1).
Square it (1) and add it to both sides.

Add '1' to each side of the equation.
-2t + 1 + t2 = 13 + 1

Reorder the terms:
1 + -2t + t2 = 13 + 1

Combine like terms: 13 + 1 = 14
1 + -2t + t2 = 14

Factor a perfect square on the left side:
(t + -1)(t + -1) = 14

Calculate the square root of the right side: 3.741657387

Break this problem into two subproblems by setting 
(t + -1) equal to 3.741657387 and -3.741657387.

Subproblem 1
t + -1 = 3.741657387

Simplifying
t + -1 = 3.741657387

Reorder the terms:
-1 + t = 3.741657387

Solving
-1 + t = 3.741657387

Solving for variable 't'.

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

Add '1' to each side of the equation.
-1 + 1 + t = 3.741657387 + 1

Combine like terms: -1 + 1 = 0
0 + t = 3.741657387 + 1
t = 3.741657387 + 1

Combine like terms: 3.741657387 + 1 = 4.741657387
t = 4.741657387

Simplifying
t = 4.741657387

Subproblem 2
t + -1 = -3.741657387

Simplifying
t + -1 = -3.741657387

Reorder the terms:
-1 + t = -3.741657387

Solving
-1 + t = -3.741657387

Solving for variable 't'.

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

Add '1' to each side of the equation.
-1 + 1 + t = -3.741657387 + 1

Combine like terms: -1 + 1 = 0
0 + t = -3.741657387 + 1
t = -3.741657387 + 1

Combine like terms: -3.741657387 + 1 = -2.741657387
t = -2.741657387

Simplifying
t = -2.741657387

Solution
The solution to the problem is based on the solutions
from the subproblems.
t = {4.741657387, -2.741657387}
Solution
t = {4.741657387, -2.741657387}