2x^2-4x=2.5

Solution for 2x^2-4x=2.5 equation:

Simplifying
2x2 + -4x = 2.5

Reorder the terms:
-4x + 2x2 = 2.5

Solving
-4x + 2x2 = 2.5

Solving for variable 'x'.

Reorder the terms:
-2.5 + -4x + 2x2 = 2.5 + -2.5

Combine like terms: 2.5 + -2.5 = 0.0
-2.5 + -4x + 2x2 = 0.0

Begin completing the square.  Divide all terms by
2 the coefficient of the squared term: 

Divide each side by '2'.
-1.25 + -2x + x2 = 0.0

Move the constant term to the right:

Add '1.25' to each side of the equation.
-1.25 + -2x + 1.25 + x2 = 0.0 + 1.25

Reorder the terms:
-1.25 + 1.25 + -2x + x2 = 0.0 + 1.25

Combine like terms: -1.25 + 1.25 = 0.00
0.00 + -2x + x2 = 0.0 + 1.25
-2x + x2 = 0.0 + 1.25

Combine like terms: 0.0 + 1.25 = 1.25
-2x + x2 = 1.25

The x term is -2x.  Take half its coefficient (-1).
Square it (1) and add it to both sides.

Add '1' to each side of the equation.
-2x + 1 + x2 = 1.25 + 1

Reorder the terms:
1 + -2x + x2 = 1.25 + 1

Combine like terms: 1.25 + 1 = 2.25
1 + -2x + x2 = 2.25

Factor a perfect square on the left side:
(x + -1)(x + -1) = 2.25

Calculate the square root of the right side: 1.5

Break this problem into two subproblems by setting 
(x + -1) equal to 1.5 and -1.5.

Subproblem 1
x + -1 = 1.5

Simplifying
x + -1 = 1.5

Reorder the terms:
-1 + x = 1.5

Solving
-1 + x = 1.5

Solving for variable 'x'.

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

Add '1' to each side of the equation.
-1 + 1 + x = 1.5 + 1

Combine like terms: -1 + 1 = 0
0 + x = 1.5 + 1
x = 1.5 + 1

Combine like terms: 1.5 + 1 = 2.5
x = 2.5

Simplifying
x = 2.5

Subproblem 2
x + -1 = -1.5

Simplifying
x + -1 = -1.5

Reorder the terms:
-1 + x = -1.5

Solving
-1 + x = -1.5

Solving for variable 'x'.

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

Add '1' to each side of the equation.
-1 + 1 + x = -1.5 + 1

Combine like terms: -1 + 1 = 0
0 + x = -1.5 + 1
x = -1.5 + 1

Combine like terms: -1.5 + 1 = -0.5
x = -0.5

Simplifying
x = -0.5

Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {2.5, -0.5}