9x^2-20x-4=0

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Solution for 9x^2-20x-4=0 equation:


Simplifying
9x2 + -20x + -4 = 0

Reorder the terms:
-4 + -20x + 9x2 = 0

Solving
-4 + -20x + 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'.
-0.4444444444 + -2.222222222x + x2 = 0

Move the constant term to the right:

Add '0.4444444444' to each side of the equation.
-0.4444444444 + -2.222222222x + 0.4444444444 + x2 = 0 + 0.4444444444

Reorder the terms:
-0.4444444444 + 0.4444444444 + -2.222222222x + x2 = 0 + 0.4444444444

Combine like terms: -0.4444444444 + 0.4444444444 = 0.0000000000
0.0000000000 + -2.222222222x + x2 = 0 + 0.4444444444
-2.222222222x + x2 = 0 + 0.4444444444

Combine like terms: 0 + 0.4444444444 = 0.4444444444
-2.222222222x + x2 = 0.4444444444

The x term is -2.222222222x.  Take half its coefficient (-1.111111111).
Square it (1.234567901) and add it to both sides.

Add '1.234567901' to each side of the equation.
-2.222222222x + 1.234567901 + x2 = 0.4444444444 + 1.234567901

Reorder the terms:
1.234567901 + -2.222222222x + x2 = 0.4444444444 + 1.234567901

Combine like terms: 0.4444444444 + 1.234567901 = 1.6790123454
1.234567901 + -2.222222222x + x2 = 1.6790123454

Factor a perfect square on the left side:
(x + -1.111111111)(x + -1.111111111) = 1.6790123454

Calculate the square root of the right side: 1.295767088

Break this problem into two subproblems by setting 
(x + -1.111111111) equal to 1.295767088 and -1.295767088.

Subproblem 1

x + -1.111111111 = 1.295767088 Simplifying x + -1.111111111 = 1.295767088 Reorder the terms: -1.111111111 + x = 1.295767088 Solving -1.111111111 + x = 1.295767088 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1.111111111' to each side of the equation. -1.111111111 + 1.111111111 + x = 1.295767088 + 1.111111111 Combine like terms: -1.111111111 + 1.111111111 = 0.000000000 0.000000000 + x = 1.295767088 + 1.111111111 x = 1.295767088 + 1.111111111 Combine like terms: 1.295767088 + 1.111111111 = 2.406878199 x = 2.406878199 Simplifying x = 2.406878199

Subproblem 2

x + -1.111111111 = -1.295767088 Simplifying x + -1.111111111 = -1.295767088 Reorder the terms: -1.111111111 + x = -1.295767088 Solving -1.111111111 + x = -1.295767088 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1.111111111' to each side of the equation. -1.111111111 + 1.111111111 + x = -1.295767088 + 1.111111111 Combine like terms: -1.111111111 + 1.111111111 = 0.000000000 0.000000000 + x = -1.295767088 + 1.111111111 x = -1.295767088 + 1.111111111 Combine like terms: -1.295767088 + 1.111111111 = -0.184655977 x = -0.184655977 Simplifying x = -0.184655977

Solution

The solution to the problem is based on the solutions from the subproblems. x = {2.406878199, -0.184655977}

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