55=x(x+6)

Solution for 55=x(x+6) equation:

Simplifying
55 = x(x + 6)

Reorder the terms:
55 = x(6 + x)
55 = (6 * x + x * x)
55 = (6x + x2)

Solving
55 = 6x + x2

Solving for variable 'x'.

Reorder the terms:
55 + -6x + -1x2 = 6x + -6x + x2 + -1x2

Combine like terms: 6x + -6x = 0
55 + -6x + -1x2 = 0 + x2 + -1x2
55 + -6x + -1x2 = x2 + -1x2

Combine like terms: x2 + -1x2 = 0
55 + -6x + -1x2 = 0

Factor a trinomial.
(5 + -1x)(11 + 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 '(11 + x)' equal to zero and attempt to solve:

Simplifying
11 + x = 0

Solving
11 + x = 0

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

Add '-11' to each side of the equation.
11 + -11 + x = 0 + -11

Combine like terms: 11 + -11 = 0
0 + x = 0 + -11
x = 0 + -11

Combine like terms: 0 + -11 = -11
x = -11

Simplifying
x = -11
Solution
x = {5, -11}