D^2-5D-6=0

Solution for D^2-5D-6=0 equation:

Simplifying
D2 + -5D + -6 = 0

Reorder the terms:
-6 + -5D + D2 = 0

Solving
-6 + -5D + D2 = 0

Solving for variable 'D'.

Factor a trinomial.
(-1 + -1D)(6 + -1D) = 0

Subproblem 1
Set the factor '(-1 + -1D)' equal to zero and attempt to solve:

Simplifying
-1 + -1D = 0

Solving
-1 + -1D = 0

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

Add '1' to each side of the equation.
-1 + 1 + -1D = 0 + 1

Combine like terms: -1 + 1 = 0
0 + -1D = 0 + 1
-1D = 0 + 1

Combine like terms: 0 + 1 = 1
-1D = 1

Divide each side by '-1'.
D = -1

Simplifying
D = -1
Subproblem 2
Set the factor '(6 + -1D)' equal to zero and attempt to solve:

Simplifying
6 + -1D = 0

Solving
6 + -1D = 0

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

Add '-6' to each side of the equation.
6 + -6 + -1D = 0 + -6

Combine like terms: 6 + -6 = 0
0 + -1D = 0 + -6
-1D = 0 + -6

Combine like terms: 0 + -6 = -6
-1D = -6

Divide each side by '-1'.
D = 6

Simplifying
D = 6
Solution
D = {-1, 6}