x^2+15x=-56

Solution for x^2+15x=-56 equation:

Simplifying
x2 + 15x = -56

Reorder the terms:
15x + x2 = -56

Solving
15x + x2 = -56

Solving for variable 'x'.

Reorder the terms:
56 + 15x + x2 = -56 + 56

Combine like terms: -56 + 56 = 0
56 + 15x + x2 = 0

Factor a trinomial.
(8 + x)(7 + x) = 0

Subproblem 1
Set the factor '(8 + x)' equal to zero and attempt to solve:

Simplifying
8 + x = 0

Solving
8 + x = 0

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

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

Combine like terms: 8 + -8 = 0
0 + x = 0 + -8
x = 0 + -8

Combine like terms: 0 + -8 = -8
x = -8

Simplifying
x = -8
Subproblem 2
Set the factor '(7 + x)' equal to zero and attempt to solve:

Simplifying
7 + x = 0

Solving
7 + x = 0

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

Add '-7' to each side of the equation.
7 + -7 + x = 0 + -7

Combine like terms: 7 + -7 = 0
0 + x = 0 + -7
x = 0 + -7

Combine like terms: 0 + -7 = -7
x = -7

Simplifying
x = -7
Solution
x = {-8, -7}