x^2+1.8x-3.19=0

Solution for x^2+1.8x-3.19=0 equation:

Simplifying
x2 + 1.8x + -3.19 = 0

Reorder the terms:
-3.19 + 1.8x + x2 = 0

Solving
-3.19 + 1.8x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '3.19' to each side of the equation.
-3.19 + 1.8x + 3.19 + x2 = 0 + 3.19

Reorder the terms:
-3.19 + 3.19 + 1.8x + x2 = 0 + 3.19

Combine like terms: -3.19 + 3.19 = 0.00
0.00 + 1.8x + x2 = 0 + 3.19
1.8x + x2 = 0 + 3.19

Combine like terms: 0 + 3.19 = 3.19
1.8x + x2 = 3.19

The x term is 1.8x.  Take half its coefficient (0.9).
Square it (0.81) and add it to both sides.

Add '0.81' to each side of the equation.
1.8x + 0.81 + x2 = 3.19 + 0.81

Reorder the terms:
0.81 + 1.8x + x2 = 3.19 + 0.81

Combine like terms: 3.19 + 0.81 = 4
0.81 + 1.8x + x2 = 4

Factor a perfect square on the left side:
(x + 0.9)(x + 0.9) = 4

Calculate the square root of the right side: 2

Break this problem into two subproblems by setting 
(x + 0.9) equal to 2 and -2.

Subproblem 1
x + 0.9 = 2

Simplifying
x + 0.9 = 2

Reorder the terms:
0.9 + x = 2

Solving
0.9 + x = 2

Solving for variable 'x'.

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

Add '-0.9' to each side of the equation.
0.9 + -0.9 + x = 2 + -0.9

Combine like terms: 0.9 + -0.9 = 0.0
0.0 + x = 2 + -0.9
x = 2 + -0.9

Combine like terms: 2 + -0.9 = 1.1
x = 1.1

Simplifying
x = 1.1

Subproblem 2
x + 0.9 = -2

Simplifying
x + 0.9 = -2

Reorder the terms:
0.9 + x = -2

Solving
0.9 + x = -2

Solving for variable 'x'.

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

Add '-0.9' to each side of the equation.
0.9 + -0.9 + x = -2 + -0.9

Combine like terms: 0.9 + -0.9 = 0.0
0.0 + x = -2 + -0.9
x = -2 + -0.9

Combine like terms: -2 + -0.9 = -2.9
x = -2.9

Simplifying
x = -2.9

Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {1.1, -2.9}