7x^2+12x-9=0

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Solution for 7x^2+12x-9=0 equation:


Simplifying
7x2 + 12x + -9 = 0

Reorder the terms:
-9 + 12x + 7x2 = 0

Solving
-9 + 12x + 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 + 1.714285714x + x2 = 0

Move the constant term to the right:

Add '1.285714286' to each side of the equation.
-1.285714286 + 1.714285714x + 1.285714286 + x2 = 0 + 1.285714286

Reorder the terms:
-1.285714286 + 1.285714286 + 1.714285714x + x2 = 0 + 1.285714286

Combine like terms: -1.285714286 + 1.285714286 = 0.000000000
0.000000000 + 1.714285714x + x2 = 0 + 1.285714286
1.714285714x + x2 = 0 + 1.285714286

Combine like terms: 0 + 1.285714286 = 1.285714286
1.714285714x + x2 = 1.285714286

The x term is 1.714285714x.  Take half its coefficient (0.857142857).
Square it (0.7346938773) and add it to both sides.

Add '0.7346938773' to each side of the equation.
1.714285714x + 0.7346938773 + x2 = 1.285714286 + 0.7346938773

Reorder the terms:
0.7346938773 + 1.714285714x + x2 = 1.285714286 + 0.7346938773

Combine like terms: 1.285714286 + 0.7346938773 = 2.0204081633
0.7346938773 + 1.714285714x + x2 = 2.0204081633

Factor a perfect square on the left side:
(x + 0.857142857)(x + 0.857142857) = 2.0204081633

Calculate the square root of the right side: 1.421410624

Break this problem into two subproblems by setting 
(x + 0.857142857) equal to 1.421410624 and -1.421410624.

Subproblem 1

x + 0.857142857 = 1.421410624 Simplifying x + 0.857142857 = 1.421410624 Reorder the terms: 0.857142857 + x = 1.421410624 Solving 0.857142857 + x = 1.421410624 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.857142857' to each side of the equation. 0.857142857 + -0.857142857 + x = 1.421410624 + -0.857142857 Combine like terms: 0.857142857 + -0.857142857 = 0.000000000 0.000000000 + x = 1.421410624 + -0.857142857 x = 1.421410624 + -0.857142857 Combine like terms: 1.421410624 + -0.857142857 = 0.564267767 x = 0.564267767 Simplifying x = 0.564267767

Subproblem 2

x + 0.857142857 = -1.421410624 Simplifying x + 0.857142857 = -1.421410624 Reorder the terms: 0.857142857 + x = -1.421410624 Solving 0.857142857 + x = -1.421410624 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.857142857' to each side of the equation. 0.857142857 + -0.857142857 + x = -1.421410624 + -0.857142857 Combine like terms: 0.857142857 + -0.857142857 = 0.000000000 0.000000000 + x = -1.421410624 + -0.857142857 x = -1.421410624 + -0.857142857 Combine like terms: -1.421410624 + -0.857142857 = -2.278553481 x = -2.278553481 Simplifying x = -2.278553481

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.564267767, -2.278553481}

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