x^2-12x=39

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Solution for x^2-12x=39 equation:


Simplifying
x2 + -12x = 39

Reorder the terms:
-12x + x2 = 39

Solving
-12x + x2 = 39

Solving for variable 'x'.

Reorder the terms:
-39 + -12x + x2 = 39 + -39

Combine like terms: 39 + -39 = 0
-39 + -12x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '39' to each side of the equation.
-39 + -12x + 39 + x2 = 0 + 39

Reorder the terms:
-39 + 39 + -12x + x2 = 0 + 39

Combine like terms: -39 + 39 = 0
0 + -12x + x2 = 0 + 39
-12x + x2 = 0 + 39

Combine like terms: 0 + 39 = 39
-12x + x2 = 39

The x term is -12x.  Take half its coefficient (-6).
Square it (36) and add it to both sides.

Add '36' to each side of the equation.
-12x + 36 + x2 = 39 + 36

Reorder the terms:
36 + -12x + x2 = 39 + 36

Combine like terms: 39 + 36 = 75
36 + -12x + x2 = 75

Factor a perfect square on the left side:
(x + -6)(x + -6) = 75

Calculate the square root of the right side: 8.660254038

Break this problem into two subproblems by setting 
(x + -6) equal to 8.660254038 and -8.660254038.

Subproblem 1

x + -6 = 8.660254038 Simplifying x + -6 = 8.660254038 Reorder the terms: -6 + x = 8.660254038 Solving -6 + x = 8.660254038 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '6' to each side of the equation. -6 + 6 + x = 8.660254038 + 6 Combine like terms: -6 + 6 = 0 0 + x = 8.660254038 + 6 x = 8.660254038 + 6 Combine like terms: 8.660254038 + 6 = 14.660254038 x = 14.660254038 Simplifying x = 14.660254038

Subproblem 2

x + -6 = -8.660254038 Simplifying x + -6 = -8.660254038 Reorder the terms: -6 + x = -8.660254038 Solving -6 + x = -8.660254038 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '6' to each side of the equation. -6 + 6 + x = -8.660254038 + 6 Combine like terms: -6 + 6 = 0 0 + x = -8.660254038 + 6 x = -8.660254038 + 6 Combine like terms: -8.660254038 + 6 = -2.660254038 x = -2.660254038 Simplifying x = -2.660254038

Solution

The solution to the problem is based on the solutions from the subproblems. x = {14.660254038, -2.660254038}

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