7x^2+13x-9=0

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Solution for 7x^2+13x-9=0 equation:


Simplifying
7x2 + 13x + -9 = 0

Reorder the terms:
-9 + 13x + 7x2 = 0

Solving
-9 + 13x + 7x2 = 0

Solving for variable 'x'.

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

Divide each side by '7'.
-1.285714286 + 1.857142857x + x2 = 0

Move the constant term to the right:

Add '1.285714286' to each side of the equation.
-1.285714286 + 1.857142857x + 1.285714286 + x2 = 0 + 1.285714286

Reorder the terms:
-1.285714286 + 1.285714286 + 1.857142857x + x2 = 0 + 1.285714286

Combine like terms: -1.285714286 + 1.285714286 = 0.000000000
0.000000000 + 1.857142857x + x2 = 0 + 1.285714286
1.857142857x + x2 = 0 + 1.285714286

Combine like terms: 0 + 1.285714286 = 1.285714286
1.857142857x + x2 = 1.285714286

The x term is 1.857142857x.  Take half its coefficient (0.9285714285).
Square it (0.8622448978) and add it to both sides.

Add '0.8622448978' to each side of the equation.
1.857142857x + 0.8622448978 + x2 = 1.285714286 + 0.8622448978

Reorder the terms:
0.8622448978 + 1.857142857x + x2 = 1.285714286 + 0.8622448978

Combine like terms: 1.285714286 + 0.8622448978 = 2.1479591838
0.8622448978 + 1.857142857x + x2 = 2.1479591838

Factor a perfect square on the left side:
(x + 0.9285714285)(x + 0.9285714285) = 2.1479591838

Calculate the square root of the right side: 1.465591752

Break this problem into two subproblems by setting 
(x + 0.9285714285) equal to 1.465591752 and -1.465591752.

Subproblem 1

x + 0.9285714285 = 1.465591752 Simplifying x + 0.9285714285 = 1.465591752 Reorder the terms: 0.9285714285 + x = 1.465591752 Solving 0.9285714285 + x = 1.465591752 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.9285714285' to each side of the equation. 0.9285714285 + -0.9285714285 + x = 1.465591752 + -0.9285714285 Combine like terms: 0.9285714285 + -0.9285714285 = 0.0000000000 0.0000000000 + x = 1.465591752 + -0.9285714285 x = 1.465591752 + -0.9285714285 Combine like terms: 1.465591752 + -0.9285714285 = 0.5370203235 x = 0.5370203235 Simplifying x = 0.5370203235

Subproblem 2

x + 0.9285714285 = -1.465591752 Simplifying x + 0.9285714285 = -1.465591752 Reorder the terms: 0.9285714285 + x = -1.465591752 Solving 0.9285714285 + x = -1.465591752 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.9285714285' to each side of the equation. 0.9285714285 + -0.9285714285 + x = -1.465591752 + -0.9285714285 Combine like terms: 0.9285714285 + -0.9285714285 = 0.0000000000 0.0000000000 + x = -1.465591752 + -0.9285714285 x = -1.465591752 + -0.9285714285 Combine like terms: -1.465591752 + -0.9285714285 = -2.3941631805 x = -2.3941631805 Simplifying x = -2.3941631805

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.5370203235, -2.3941631805}

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