d^2-13d+40=0

Solution for d^2-13d+40=0 equation:

Simplifying
d2 + -13d + 40 = 0

Reorder the terms:
40 + -13d + d2 = 0

Solving
40 + -13d + d2 = 0

Solving for variable 'd'.

Factor a trinomial.
(5 + -1d)(8 + -1d) = 0

Subproblem 1
Set the factor '(5 + -1d)' equal to zero and attempt to solve:

Simplifying
5 + -1d = 0

Solving
5 + -1d = 0

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

Add '-5' to each side of the equation.
5 + -5 + -1d = 0 + -5

Combine like terms: 5 + -5 = 0
0 + -1d = 0 + -5
-1d = 0 + -5

Combine like terms: 0 + -5 = -5
-1d = -5

Divide each side by '-1'.
d = 5

Simplifying
d = 5
Subproblem 2
Set the factor '(8 + -1d)' equal to zero and attempt to solve:

Simplifying
8 + -1d = 0

Solving
8 + -1d = 0

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

Add '-8' to each side of the equation.
8 + -8 + -1d = 0 + -8

Combine like terms: 8 + -8 = 0
0 + -1d = 0 + -8
-1d = 0 + -8

Combine like terms: 0 + -8 = -8
-1d = -8

Divide each side by '-1'.
d = 8

Simplifying
d = 8
Solution
d = {5, 8}