x^2=39x-40

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Solution for x^2=39x-40 equation:


Simplifying
x2 = 39x + -40

Reorder the terms:
x2 = -40 + 39x

Solving
x2 = -40 + 39x

Solving for variable 'x'.

Reorder the terms:
40 + -39x + x2 = -40 + 39x + 40 + -39x

Reorder the terms:
40 + -39x + x2 = -40 + 40 + 39x + -39x

Combine like terms: -40 + 40 = 0
40 + -39x + x2 = 0 + 39x + -39x
40 + -39x + x2 = 39x + -39x

Combine like terms: 39x + -39x = 0
40 + -39x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '-40' to each side of the equation.
40 + -39x + -40 + x2 = 0 + -40

Reorder the terms:
40 + -40 + -39x + x2 = 0 + -40

Combine like terms: 40 + -40 = 0
0 + -39x + x2 = 0 + -40
-39x + x2 = 0 + -40

Combine like terms: 0 + -40 = -40
-39x + x2 = -40

The x term is -39x.  Take half its coefficient (-19.5).
Square it (380.25) and add it to both sides.

Add '380.25' to each side of the equation.
-39x + 380.25 + x2 = -40 + 380.25

Reorder the terms:
380.25 + -39x + x2 = -40 + 380.25

Combine like terms: -40 + 380.25 = 340.25
380.25 + -39x + x2 = 340.25

Factor a perfect square on the left side:
(x + -19.5)(x + -19.5) = 340.25

Calculate the square root of the right side: 18.445866746

Break this problem into two subproblems by setting 
(x + -19.5) equal to 18.445866746 and -18.445866746.

Subproblem 1

x + -19.5 = 18.445866746 Simplifying x + -19.5 = 18.445866746 Reorder the terms: -19.5 + x = 18.445866746 Solving -19.5 + x = 18.445866746 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '19.5' to each side of the equation. -19.5 + 19.5 + x = 18.445866746 + 19.5 Combine like terms: -19.5 + 19.5 = 0.0 0.0 + x = 18.445866746 + 19.5 x = 18.445866746 + 19.5 Combine like terms: 18.445866746 + 19.5 = 37.945866746 x = 37.945866746 Simplifying x = 37.945866746

Subproblem 2

x + -19.5 = -18.445866746 Simplifying x + -19.5 = -18.445866746 Reorder the terms: -19.5 + x = -18.445866746 Solving -19.5 + x = -18.445866746 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '19.5' to each side of the equation. -19.5 + 19.5 + x = -18.445866746 + 19.5 Combine like terms: -19.5 + 19.5 = 0.0 0.0 + x = -18.445866746 + 19.5 x = -18.445866746 + 19.5 Combine like terms: -18.445866746 + 19.5 = 1.054133254 x = 1.054133254 Simplifying x = 1.054133254

Solution

The solution to the problem is based on the solutions from the subproblems. x = {37.945866746, 1.054133254}

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