-6t^2-t-15=0

Solution for -6t^2-t-15=0 equation:

Simplifying
-6t2 + -1t + -15 = 0

Reorder the terms:
-15 + -1t + -6t2 = 0

Solving
-15 + -1t + -6t2 = 0

Solving for variable 't'.

Factor out the Greatest Common Factor (GCF), '-1'.
-1(15 + t + 6t2) = 0

Ignore the factor -1.
Subproblem 1
Set the factor '(15 + t + 6t2)' equal to zero and attempt to solve:

Simplifying
15 + t + 6t2 = 0

Solving
15 + t + 6t2 = 0

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

Divide each side by '6'.
2.5 + 0.1666666667t + t2 = 0

Move the constant term to the right:

Add '-2.5' to each side of the equation.
2.5 + 0.1666666667t + -2.5 + t2 = 0 + -2.5

Reorder the terms:
2.5 + -2.5 + 0.1666666667t + t2 = 0 + -2.5

Combine like terms: 2.5 + -2.5 = 0.0
0.0 + 0.1666666667t + t2 = 0 + -2.5
0.1666666667t + t2 = 0 + -2.5

Combine like terms: 0 + -2.5 = -2.5
0.1666666667t + t2 = -2.5

The t term is t.  Take half its coefficient (0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
0.1666666667t + 0.25 + t2 = -2.5 + 0.25

Reorder the terms:
0.25 + 0.1666666667t + t2 = -2.5 + 0.25

Combine like terms: -2.5 + 0.25 = -2.25
0.25 + 0.1666666667t + t2 = -2.25

Factor a perfect square on the left side:
(t + 0.5)(t + 0.5) = -2.25

Can't calculate square root of the right side.

The solution to this equation could not be determined.

This subproblem is being ignored because a solution could not be determined.

The solution to this equation could not be determined.