x^2+18x+42=-3

Solution for x^2+18x+42=-3 equation:

Simplifying
x2 + 18x + 42 = -3

Reorder the terms:
42 + 18x + x2 = -3

Solving
42 + 18x + x2 = -3

Solving for variable 'x'.

Reorder the terms:
42 + 3 + 18x + x2 = -3 + 3

Combine like terms: 42 + 3 = 45
45 + 18x + x2 = -3 + 3

Combine like terms: -3 + 3 = 0
45 + 18x + x2 = 0

Factor a trinomial.
(15 + x)(3 + 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 '(3 + x)' equal to zero and attempt to solve:

Simplifying
3 + x = 0

Solving
3 + x = 0

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

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

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

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

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