x^2+2.20x+1.21=0

Solution for x^2+2.20x+1.21=0 equation:

Simplifying
x2 + 2.20x + 1.21 = 0

Reorder the terms:
1.21 + 2.20x + x2 = 0

Solving
1.21 + 2.20x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '-1.21' to each side of the equation.
1.21 + 2.20x + -1.21 + x2 = 0 + -1.21

Reorder the terms:
1.21 + -1.21 + 2.20x + x2 = 0 + -1.21

Combine like terms: 1.21 + -1.21 = 0.00
0.00 + 2.20x + x2 = 0 + -1.21
2.20x + x2 = 0 + -1.21

Combine like terms: 0 + -1.21 = -1.21
2.20x + x2 = -1.21

The x term is 2.20x.  Take half its coefficient (1.1).
Square it (1.21) and add it to both sides.

Add '1.21' to each side of the equation.
2.20x + 1.21 + x2 = -1.21 + 1.21

Reorder the terms:
1.21 + 2.20x + x2 = -1.21 + 1.21

Combine like terms: -1.21 + 1.21 = 0.00
1.21 + 2.20x + x2 = 0.00

Factor a perfect square on the left side:
(x + 1.1)(x + 1.1) = 0.00

Calculate the square root of the right side: 0.00

Break this problem into two subproblems by setting 
(x + 1.1) equal to 0.00 and 0.00.

Subproblem 1
x + 1.1 = 0.00

Simplifying
x + 1.1 = 0.00

Reorder the terms:
1.1 + x = 0.00

Solving
1.1 + x = 0.00

Solving for variable 'x'.

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

Add '-1.1' to each side of the equation.
1.1 + -1.1 + x = 0.00 + -1.1

Combine like terms: 1.1 + -1.1 = 0.0
0.0 + x = 0.00 + -1.1
x = 0.00 + -1.1

Combine like terms: 0.00 + -1.1 = -1.1
x = -1.1

Simplifying
x = -1.1

Subproblem 2
x + 1.1 = 0.00

Simplifying
x + 1.1 = 0.00

Reorder the terms:
1.1 + x = 0.00

Solving
1.1 + x = 0.00

Solving for variable 'x'.

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

Add '-1.1' to each side of the equation.
1.1 + -1.1 + x = 0.00 + -1.1

Combine like terms: 1.1 + -1.1 = 0.0
0.0 + x = 0.00 + -1.1
x = 0.00 + -1.1

Combine like terms: 0.00 + -1.1 = -1.1
x = -1.1

Simplifying
x = -1.1

Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {-1.1, -1.1}