8x^2+8x-9=0

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Solution for 8x^2+8x-9=0 equation:


Simplifying
8x2 + 8x + -9 = 0

Reorder the terms:
-9 + 8x + 8x2 = 0

Solving
-9 + 8x + 8x2 = 0

Solving for variable 'x'.

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

Divide each side by '8'.
-1.125 + x + x2 = 0

Move the constant term to the right:

Add '1.125' to each side of the equation.
-1.125 + x + 1.125 + x2 = 0 + 1.125

Reorder the terms:
-1.125 + 1.125 + x + x2 = 0 + 1.125

Combine like terms: -1.125 + 1.125 = 0.000
0.000 + x + x2 = 0 + 1.125
x + x2 = 0 + 1.125

Combine like terms: 0 + 1.125 = 1.125
x + x2 = 1.125

The x term is x.  Take half its coefficient (0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
 + 0.25 + x2 = 1.125 + 0.25

Combine like terms:  + 0.25 = 1.25
1.25 + x2 = 1.125 + 0.25

Combine like terms: 1.125 + 0.25 = 1.375
1.25 + x2 = 1.375

Factor a perfect square on the left side:
(x + 0.5)(x + 0.5) = 1.375

Calculate the square root of the right side: 1.17260394

Break this problem into two subproblems by setting 
(x + 0.5) equal to 1.17260394 and -1.17260394.

Subproblem 1

x + 0.5 = 1.17260394 Simplifying x + 0.5 = 1.17260394 Reorder the terms: 0.5 + x = 1.17260394 Solving 0.5 + x = 1.17260394 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5' to each side of the equation. 0.5 + -0.5 + x = 1.17260394 + -0.5 Combine like terms: 0.5 + -0.5 = 0.0 0.0 + x = 1.17260394 + -0.5 x = 1.17260394 + -0.5 Combine like terms: 1.17260394 + -0.5 = 0.67260394 x = 0.67260394 Simplifying x = 0.67260394

Subproblem 2

x + 0.5 = -1.17260394 Simplifying x + 0.5 = -1.17260394 Reorder the terms: 0.5 + x = -1.17260394 Solving 0.5 + x = -1.17260394 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5' to each side of the equation. 0.5 + -0.5 + x = -1.17260394 + -0.5 Combine like terms: 0.5 + -0.5 = 0.0 0.0 + x = -1.17260394 + -0.5 x = -1.17260394 + -0.5 Combine like terms: -1.17260394 + -0.5 = -1.67260394 x = -1.67260394 Simplifying x = -1.67260394

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.67260394, -1.67260394}

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