9x^2-7x-85=0

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Solution for 9x^2-7x-85=0 equation:


Simplifying
9x2 + -7x + -85 = 0

Reorder the terms:
-85 + -7x + 9x2 = 0

Solving
-85 + -7x + 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'.
-9.444444444 + -0.7777777778x + x2 = 0

Move the constant term to the right:

Add '9.444444444' to each side of the equation.
-9.444444444 + -0.7777777778x + 9.444444444 + x2 = 0 + 9.444444444

Reorder the terms:
-9.444444444 + 9.444444444 + -0.7777777778x + x2 = 0 + 9.444444444

Combine like terms: -9.444444444 + 9.444444444 = 0.000000000
0.000000000 + -0.7777777778x + x2 = 0 + 9.444444444
-0.7777777778x + x2 = 0 + 9.444444444

Combine like terms: 0 + 9.444444444 = 9.444444444
-0.7777777778x + x2 = 9.444444444

The x term is -0.7777777778x.  Take half its coefficient (-0.3888888889).
Square it (0.1512345679) and add it to both sides.

Add '0.1512345679' to each side of the equation.
-0.7777777778x + 0.1512345679 + x2 = 9.444444444 + 0.1512345679

Reorder the terms:
0.1512345679 + -0.7777777778x + x2 = 9.444444444 + 0.1512345679

Combine like terms: 9.444444444 + 0.1512345679 = 9.5956790119
0.1512345679 + -0.7777777778x + x2 = 9.5956790119

Factor a perfect square on the left side:
(x + -0.3888888889)(x + -0.3888888889) = 9.5956790119

Calculate the square root of the right side: 3.097689302

Break this problem into two subproblems by setting 
(x + -0.3888888889) equal to 3.097689302 and -3.097689302.

Subproblem 1

x + -0.3888888889 = 3.097689302 Simplifying x + -0.3888888889 = 3.097689302 Reorder the terms: -0.3888888889 + x = 3.097689302 Solving -0.3888888889 + x = 3.097689302 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.3888888889' to each side of the equation. -0.3888888889 + 0.3888888889 + x = 3.097689302 + 0.3888888889 Combine like terms: -0.3888888889 + 0.3888888889 = 0.0000000000 0.0000000000 + x = 3.097689302 + 0.3888888889 x = 3.097689302 + 0.3888888889 Combine like terms: 3.097689302 + 0.3888888889 = 3.4865781909 x = 3.4865781909 Simplifying x = 3.4865781909

Subproblem 2

x + -0.3888888889 = -3.097689302 Simplifying x + -0.3888888889 = -3.097689302 Reorder the terms: -0.3888888889 + x = -3.097689302 Solving -0.3888888889 + x = -3.097689302 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.3888888889' to each side of the equation. -0.3888888889 + 0.3888888889 + x = -3.097689302 + 0.3888888889 Combine like terms: -0.3888888889 + 0.3888888889 = 0.0000000000 0.0000000000 + x = -3.097689302 + 0.3888888889 x = -3.097689302 + 0.3888888889 Combine like terms: -3.097689302 + 0.3888888889 = -2.7088004131 x = -2.7088004131 Simplifying x = -2.7088004131

Solution

The solution to the problem is based on the solutions from the subproblems. x = {3.4865781909, -2.7088004131}

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