-x^2+31x-8=0

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Solution for -x^2+31x-8=0 equation:


Simplifying
-1x2 + 31x + -8 = 0

Reorder the terms:
-8 + 31x + -1x2 = 0

Solving
-8 + 31x + -1x2 = 0

Solving for variable 'x'.

Begin completing the square.  Divide all terms by
-1 the coefficient of the squared term: 

Divide each side by '-1'.
8 + -31x + x2 = 0

Move the constant term to the right:

Add '-8' to each side of the equation.
8 + -31x + -8 + x2 = 0 + -8

Reorder the terms:
8 + -8 + -31x + x2 = 0 + -8

Combine like terms: 8 + -8 = 0
0 + -31x + x2 = 0 + -8
-31x + x2 = 0 + -8

Combine like terms: 0 + -8 = -8
-31x + x2 = -8

The x term is -31x.  Take half its coefficient (-15.5).
Square it (240.25) and add it to both sides.

Add '240.25' to each side of the equation.
-31x + 240.25 + x2 = -8 + 240.25

Reorder the terms:
240.25 + -31x + x2 = -8 + 240.25

Combine like terms: -8 + 240.25 = 232.25
240.25 + -31x + x2 = 232.25

Factor a perfect square on the left side:
(x + -15.5)(x + -15.5) = 232.25

Calculate the square root of the right side: 15.239750654

Break this problem into two subproblems by setting 
(x + -15.5) equal to 15.239750654 and -15.239750654.

Subproblem 1

x + -15.5 = 15.239750654 Simplifying x + -15.5 = 15.239750654 Reorder the terms: -15.5 + x = 15.239750654 Solving -15.5 + x = 15.239750654 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '15.5' to each side of the equation. -15.5 + 15.5 + x = 15.239750654 + 15.5 Combine like terms: -15.5 + 15.5 = 0.0 0.0 + x = 15.239750654 + 15.5 x = 15.239750654 + 15.5 Combine like terms: 15.239750654 + 15.5 = 30.739750654 x = 30.739750654 Simplifying x = 30.739750654

Subproblem 2

x + -15.5 = -15.239750654 Simplifying x + -15.5 = -15.239750654 Reorder the terms: -15.5 + x = -15.239750654 Solving -15.5 + x = -15.239750654 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '15.5' to each side of the equation. -15.5 + 15.5 + x = -15.239750654 + 15.5 Combine like terms: -15.5 + 15.5 = 0.0 0.0 + x = -15.239750654 + 15.5 x = -15.239750654 + 15.5 Combine like terms: -15.239750654 + 15.5 = 0.260249346 x = 0.260249346 Simplifying x = 0.260249346

Solution

The solution to the problem is based on the solutions from the subproblems. x = {30.739750654, 0.260249346}

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