(m+15)(m-3)=0

Solution for (m+15)(m-3)=0 equation:

Simplifying
(m + 15)(m + -3) = 0

Reorder the terms:
(15 + m)(m + -3) = 0

Reorder the terms:
(15 + m)(-3 + m) = 0

Multiply (15 + m) * (-3 + m)
(15(-3 + m) + m(-3 + m)) = 0
((-3 * 15 + m * 15) + m(-3 + m)) = 0
((-45 + 15m) + m(-3 + m)) = 0
(-45 + 15m + (-3 * m + m * m)) = 0
(-45 + 15m + (-3m + m2)) = 0

Combine like terms: 15m + -3m = 12m
(-45 + 12m + m2) = 0

Solving
-45 + 12m + m2 = 0

Solving for variable 'm'.

Factor a trinomial.
(-15 + -1m)(3 + -1m) = 0

Subproblem 1
Set the factor '(-15 + -1m)' equal to zero and attempt to solve:

Simplifying
-15 + -1m = 0

Solving
-15 + -1m = 0

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

Add '15' to each side of the equation.
-15 + 15 + -1m = 0 + 15

Combine like terms: -15 + 15 = 0
0 + -1m = 0 + 15
-1m = 0 + 15

Combine like terms: 0 + 15 = 15
-1m = 15

Divide each side by '-1'.
m = -15

Simplifying
m = -15
Subproblem 2
Set the factor '(3 + -1m)' equal to zero and attempt to solve:

Simplifying
3 + -1m = 0

Solving
3 + -1m = 0

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

Add '-3' to each side of the equation.
3 + -3 + -1m = 0 + -3

Combine like terms: 3 + -3 = 0
0 + -1m = 0 + -3
-1m = 0 + -3

Combine like terms: 0 + -3 = -3
-1m = -3

Divide each side by '-1'.
m = 3

Simplifying
m = 3
Solution
m = {-15, 3}