9x^2-2x-8=0

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


Simplifying
9x2 + -2x + -8 = 0

Reorder the terms:
-8 + -2x + 9x2 = 0

Solving
-8 + -2x + 9x2 = 0

Solving for variable 'x'.

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

Divide each side by '9'.
-0.8888888889 + -0.2222222222x + x2 = 0

Move the constant term to the right:

Add '0.8888888889' to each side of the equation.
-0.8888888889 + -0.2222222222x + 0.8888888889 + x2 = 0 + 0.8888888889

Reorder the terms:
-0.8888888889 + 0.8888888889 + -0.2222222222x + x2 = 0 + 0.8888888889

Combine like terms: -0.8888888889 + 0.8888888889 = 0.0000000000
0.0000000000 + -0.2222222222x + x2 = 0 + 0.8888888889
-0.2222222222x + x2 = 0 + 0.8888888889

Combine like terms: 0 + 0.8888888889 = 0.8888888889
-0.2222222222x + x2 = 0.8888888889

The x term is -0.2222222222x.  Take half its coefficient (-0.1111111111).
Square it (0.01234567901) and add it to both sides.

Add '0.01234567901' to each side of the equation.
-0.2222222222x + 0.01234567901 + x2 = 0.8888888889 + 0.01234567901

Reorder the terms:
0.01234567901 + -0.2222222222x + x2 = 0.8888888889 + 0.01234567901

Combine like terms: 0.8888888889 + 0.01234567901 = 0.90123456791
0.01234567901 + -0.2222222222x + x2 = 0.90123456791

Factor a perfect square on the left side:
(x + -0.1111111111)(x + -0.1111111111) = 0.90123456791

Calculate the square root of the right side: 0.949333749

Break this problem into two subproblems by setting 
(x + -0.1111111111) equal to 0.949333749 and -0.949333749.

Subproblem 1

x + -0.1111111111 = 0.949333749 Simplifying x + -0.1111111111 = 0.949333749 Reorder the terms: -0.1111111111 + x = 0.949333749 Solving -0.1111111111 + x = 0.949333749 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.1111111111' to each side of the equation. -0.1111111111 + 0.1111111111 + x = 0.949333749 + 0.1111111111 Combine like terms: -0.1111111111 + 0.1111111111 = 0.0000000000 0.0000000000 + x = 0.949333749 + 0.1111111111 x = 0.949333749 + 0.1111111111 Combine like terms: 0.949333749 + 0.1111111111 = 1.0604448601 x = 1.0604448601 Simplifying x = 1.0604448601

Subproblem 2

x + -0.1111111111 = -0.949333749 Simplifying x + -0.1111111111 = -0.949333749 Reorder the terms: -0.1111111111 + x = -0.949333749 Solving -0.1111111111 + x = -0.949333749 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.1111111111' to each side of the equation. -0.1111111111 + 0.1111111111 + x = -0.949333749 + 0.1111111111 Combine like terms: -0.1111111111 + 0.1111111111 = 0.0000000000 0.0000000000 + x = -0.949333749 + 0.1111111111 x = -0.949333749 + 0.1111111111 Combine like terms: -0.949333749 + 0.1111111111 = -0.8382226379 x = -0.8382226379 Simplifying x = -0.8382226379

Solution

The solution to the problem is based on the solutions from the subproblems. x = {1.0604448601, -0.8382226379}

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