(x+1)(x+15)=0

Solution for (x+1)(x+15)=0 equation:

Simplifying
(x + 1)(x + 15) = 0

Reorder the terms:
(1 + x)(x + 15) = 0

Reorder the terms:
(1 + x)(15 + x) = 0

Multiply (1 + x) * (15 + x)
(1(15 + x) + x(15 + x)) = 0
((15 * 1 + x * 1) + x(15 + x)) = 0
((15 + 1x) + x(15 + x)) = 0
(15 + 1x + (15 * x + x * x)) = 0
(15 + 1x + (15x + x2)) = 0

Combine like terms: 1x + 15x = 16x
(15 + 16x + x2) = 0

Solving
15 + 16x + x2 = 0

Solving for variable 'x'.

Factor a trinomial.
(15 + x)(1 + x) = 0

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

Simplifying
15 + x = 0

Solving
15 + x = 0

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

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

Combine like terms: 15 + -15 = 0
0 + x = 0 + -15
x = 0 + -15

Combine like terms: 0 + -15 = -15
x = -15

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

Simplifying
1 + x = 0

Solving
1 + x = 0

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

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

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

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

Simplifying
x = -1
Solution
x = {-15, -1}