7x^2+5x=9

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Solution for 7x^2+5x=9 equation:


Simplifying
7x2 + 5x = 9

Reorder the terms:
5x + 7x2 = 9

Solving
5x + 7x2 = 9

Solving for variable 'x'.

Reorder the terms:
-9 + 5x + 7x2 = 9 + -9

Combine like terms: 9 + -9 = 0
-9 + 5x + 7x2 = 0

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

Divide each side by '7'.
-1.285714286 + 0.7142857143x + x2 = 0

Move the constant term to the right:

Add '1.285714286' to each side of the equation.
-1.285714286 + 0.7142857143x + 1.285714286 + x2 = 0 + 1.285714286

Reorder the terms:
-1.285714286 + 1.285714286 + 0.7142857143x + x2 = 0 + 1.285714286

Combine like terms: -1.285714286 + 1.285714286 = 0.000000000
0.000000000 + 0.7142857143x + x2 = 0 + 1.285714286
0.7142857143x + x2 = 0 + 1.285714286

Combine like terms: 0 + 1.285714286 = 1.285714286
0.7142857143x + x2 = 1.285714286

The x term is 0.7142857143x.  Take half its coefficient (0.3571428572).
Square it (0.1275510204) and add it to both sides.

Add '0.1275510204' to each side of the equation.
0.7142857143x + 0.1275510204 + x2 = 1.285714286 + 0.1275510204

Reorder the terms:
0.1275510204 + 0.7142857143x + x2 = 1.285714286 + 0.1275510204

Combine like terms: 1.285714286 + 0.1275510204 = 1.4132653064
0.1275510204 + 0.7142857143x + x2 = 1.4132653064

Factor a perfect square on the left side:
(x + 0.3571428572)(x + 0.3571428572) = 1.4132653064

Calculate the square root of the right side: 1.188808356

Break this problem into two subproblems by setting 
(x + 0.3571428572) equal to 1.188808356 and -1.188808356.

Subproblem 1

x + 0.3571428572 = 1.188808356 Simplifying x + 0.3571428572 = 1.188808356 Reorder the terms: 0.3571428572 + x = 1.188808356 Solving 0.3571428572 + x = 1.188808356 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.3571428572' to each side of the equation. 0.3571428572 + -0.3571428572 + x = 1.188808356 + -0.3571428572 Combine like terms: 0.3571428572 + -0.3571428572 = 0.0000000000 0.0000000000 + x = 1.188808356 + -0.3571428572 x = 1.188808356 + -0.3571428572 Combine like terms: 1.188808356 + -0.3571428572 = 0.8316654988 x = 0.8316654988 Simplifying x = 0.8316654988

Subproblem 2

x + 0.3571428572 = -1.188808356 Simplifying x + 0.3571428572 = -1.188808356 Reorder the terms: 0.3571428572 + x = -1.188808356 Solving 0.3571428572 + x = -1.188808356 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.3571428572' to each side of the equation. 0.3571428572 + -0.3571428572 + x = -1.188808356 + -0.3571428572 Combine like terms: 0.3571428572 + -0.3571428572 = 0.0000000000 0.0000000000 + x = -1.188808356 + -0.3571428572 x = -1.188808356 + -0.3571428572 Combine like terms: -1.188808356 + -0.3571428572 = -1.5459512132 x = -1.5459512132 Simplifying x = -1.5459512132

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.8316654988, -1.5459512132}

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