15=k^2-2k

Solution for 15=k^2-2k equation:

Simplifying
15 = k2 + -2k

Reorder the terms:
15 = -2k + k2

Solving
15 = -2k + k2

Solving for variable 'k'.

Reorder the terms:
15 + 2k + -1k2 = -2k + 2k + k2 + -1k2

Combine like terms: -2k + 2k = 0
15 + 2k + -1k2 = 0 + k2 + -1k2
15 + 2k + -1k2 = k2 + -1k2

Combine like terms: k2 + -1k2 = 0
15 + 2k + -1k2 = 0

Factor a trinomial.
(5 + -1k)(3 + k) = 0

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

Simplifying
5 + -1k = 0

Solving
5 + -1k = 0

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

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

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

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

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

Simplifying
k = 5
Subproblem 2
Set the factor '(3 + k)' equal to zero and attempt to solve:

Simplifying
3 + k = 0

Solving
3 + k = 0

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

Add '-3' to each side of the equation.
3 + -3 + k = 0 + -3

Combine like terms: 3 + -3 = 0
0 + k = 0 + -3
k = 0 + -3

Combine like terms: 0 + -3 = -3
k = -3

Simplifying
k = -3
Solution
k = {5, -3}