100=X^2+15X

Solution for 100=X^2+15X equation:

Simplifying
100 = X2 + 15X

Reorder the terms:
100 = 15X + X2

Solving
100 = 15X + X2

Solving for variable 'X'.

Reorder the terms:
100 + -15X + -1X2 = 15X + -15X + X2 + -1X2

Combine like terms: 15X + -15X = 0
100 + -15X + -1X2 = 0 + X2 + -1X2
100 + -15X + -1X2 = X2 + -1X2

Combine like terms: X2 + -1X2 = 0
100 + -15X + -1X2 = 0

Factor a trinomial.
(5 + -1X)(20 + X) = 0

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

Simplifying
5 + -1X = 0

Solving
5 + -1X = 0

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

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

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

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

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

Simplifying
X = 5
Subproblem 2
Set the factor '(20 + X)' equal to zero and attempt to solve:

Simplifying
20 + X = 0

Solving
20 + X = 0

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

Add '-20' to each side of the equation.
20 + -20 + X = 0 + -20

Combine like terms: 20 + -20 = 0
0 + X = 0 + -20
X = 0 + -20

Combine like terms: 0 + -20 = -20
X = -20

Simplifying
X = -20
Solution
X = {5, -20}