(x)(2x+1)=55

Solution for (x)(2x+1)=55 equation:

Simplifying
(x)(2x + 1) = 55

Reorder the terms:
x(1 + 2x) = 55
(1 * x + 2x * x) = 55
(1x + 2x2) = 55

Solving
1x + 2x2 = 55

Solving for variable 'x'.

Reorder the terms:
-55 + 1x + 2x2 = 55 + -55

Combine like terms: 55 + -55 = 0
-55 + 1x + 2x2 = 0

Factor a trinomial.
(-11 + -2x)(5 + -1x) = 0

Subproblem 1
Set the factor '(-11 + -2x)' equal to zero and attempt to solve:

Simplifying
-11 + -2x = 0

Solving
-11 + -2x = 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 + -2x = 0 + 11

Combine like terms: -11 + 11 = 0
0 + -2x = 0 + 11
-2x = 0 + 11

Combine like terms: 0 + 11 = 11
-2x = 11

Divide each side by '-2'.
x = -5.5

Simplifying
x = -5.5
Subproblem 2
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
Solution
x = {-5.5, 5}