-9x^2+7x+9=0

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


Simplifying
-9x2 + 7x + 9 = 0

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

Solving
9 + 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'.
-1 + -0.7777777778x + x2 = 0

Move the constant term to the right:

Add '1' to each side of the equation.
-1 + -0.7777777778x + 1 + x2 = 0 + 1

Reorder the terms:
-1 + 1 + -0.7777777778x + x2 = 0 + 1

Combine like terms: -1 + 1 = 0
0 + -0.7777777778x + x2 = 0 + 1
-0.7777777778x + x2 = 0 + 1

Combine like terms: 0 + 1 = 1
-0.7777777778x + x2 = 1

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 = 1 + 0.1512345679

Reorder the terms:
0.1512345679 + -0.7777777778x + x2 = 1 + 0.1512345679

Combine like terms: 1 + 0.1512345679 = 1.1512345679
0.1512345679 + -0.7777777778x + x2 = 1.1512345679

Factor a perfect square on the left side:
(x + -0.3888888889)(x + -0.3888888889) = 1.1512345679

Calculate the square root of the right side: 1.072955995

Break this problem into two subproblems by setting 
(x + -0.3888888889) equal to 1.072955995 and -1.072955995.

Subproblem 1

x + -0.3888888889 = 1.072955995 Simplifying x + -0.3888888889 = 1.072955995 Reorder the terms: -0.3888888889 + x = 1.072955995 Solving -0.3888888889 + x = 1.072955995 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 = 1.072955995 + 0.3888888889 Combine like terms: -0.3888888889 + 0.3888888889 = 0.0000000000 0.0000000000 + x = 1.072955995 + 0.3888888889 x = 1.072955995 + 0.3888888889 Combine like terms: 1.072955995 + 0.3888888889 = 1.4618448839 x = 1.4618448839 Simplifying x = 1.4618448839

Subproblem 2

x + -0.3888888889 = -1.072955995 Simplifying x + -0.3888888889 = -1.072955995 Reorder the terms: -0.3888888889 + x = -1.072955995 Solving -0.3888888889 + x = -1.072955995 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 = -1.072955995 + 0.3888888889 Combine like terms: -0.3888888889 + 0.3888888889 = 0.0000000000 0.0000000000 + x = -1.072955995 + 0.3888888889 x = -1.072955995 + 0.3888888889 Combine like terms: -1.072955995 + 0.3888888889 = -0.6840671061 x = -0.6840671061 Simplifying x = -0.6840671061

Solution

The solution to the problem is based on the solutions from the subproblems. x = {1.4618448839, -0.6840671061}

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