x^2+1.4x-5.76=0

Solution for x^2+1.4x-5.76=0 equation:

Simplifying
x2 + 1.4x + -5.76 = 0

Reorder the terms:
-5.76 + 1.4x + x2 = 0

Solving
-5.76 + 1.4x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '5.76' to each side of the equation.
-5.76 + 1.4x + 5.76 + x2 = 0 + 5.76

Reorder the terms:
-5.76 + 5.76 + 1.4x + x2 = 0 + 5.76

Combine like terms: -5.76 + 5.76 = 0.00
0.00 + 1.4x + x2 = 0 + 5.76
1.4x + x2 = 0 + 5.76

Combine like terms: 0 + 5.76 = 5.76
1.4x + x2 = 5.76

The x term is 1.4x.  Take half its coefficient (0.7).
Square it (0.49) and add it to both sides.

Add '0.49' to each side of the equation.
1.4x + 0.49 + x2 = 5.76 + 0.49

Reorder the terms:
0.49 + 1.4x + x2 = 5.76 + 0.49

Combine like terms: 5.76 + 0.49 = 6.25
0.49 + 1.4x + x2 = 6.25

Factor a perfect square on the left side:
(x + 0.7)(x + 0.7) = 6.25

Calculate the square root of the right side: 2.5

Break this problem into two subproblems by setting 
(x + 0.7) equal to 2.5 and -2.5.

Subproblem 1
x + 0.7 = 2.5

Simplifying
x + 0.7 = 2.5

Reorder the terms:
0.7 + x = 2.5

Solving
0.7 + x = 2.5

Solving for variable 'x'.

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

Add '-0.7' to each side of the equation.
0.7 + -0.7 + x = 2.5 + -0.7

Combine like terms: 0.7 + -0.7 = 0.0
0.0 + x = 2.5 + -0.7
x = 2.5 + -0.7

Combine like terms: 2.5 + -0.7 = 1.8
x = 1.8

Simplifying
x = 1.8

Subproblem 2
x + 0.7 = -2.5

Simplifying
x + 0.7 = -2.5

Reorder the terms:
0.7 + x = -2.5

Solving
0.7 + x = -2.5

Solving for variable 'x'.

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

Add '-0.7' to each side of the equation.
0.7 + -0.7 + x = -2.5 + -0.7

Combine like terms: 0.7 + -0.7 = 0.0
0.0 + x = -2.5 + -0.7
x = -2.5 + -0.7

Combine like terms: -2.5 + -0.7 = -3.2
x = -3.2

Simplifying
x = -3.2

Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {1.8, -3.2}