81x^2+27x-5=0

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Solution for 81x^2+27x-5=0 equation:


Simplifying
81x2 + 27x + -5 = 0

Reorder the terms:
-5 + 27x + 81x2 = 0

Solving
-5 + 27x + 81x2 = 0

Solving for variable 'x'.

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

Divide each side by '81'.
-0.06172839506 + 0.3333333333x + x2 = 0

Move the constant term to the right:

Add '0.06172839506' to each side of the equation.
-0.06172839506 + 0.3333333333x + 0.06172839506 + x2 = 0 + 0.06172839506

Reorder the terms:
-0.06172839506 + 0.06172839506 + 0.3333333333x + x2 = 0 + 0.06172839506

Combine like terms: -0.06172839506 + 0.06172839506 = 0.00000000000
0.00000000000 + 0.3333333333x + x2 = 0 + 0.06172839506
0.3333333333x + x2 = 0 + 0.06172839506

Combine like terms: 0 + 0.06172839506 = 0.06172839506
0.3333333333x + x2 = 0.06172839506

The x term is 0.3333333333x.  Take half its coefficient (0.1666666667).
Square it (0.02777777779) and add it to both sides.

Add '0.02777777779' to each side of the equation.
0.3333333333x + 0.02777777779 + x2 = 0.06172839506 + 0.02777777779

Reorder the terms:
0.02777777779 + 0.3333333333x + x2 = 0.06172839506 + 0.02777777779

Combine like terms: 0.06172839506 + 0.02777777779 = 0.08950617285
0.02777777779 + 0.3333333333x + x2 = 0.08950617285

Factor a perfect square on the left side:
(x + 0.1666666667)(x + 0.1666666667) = 0.08950617285

Calculate the square root of the right side: 0.299175823

Break this problem into two subproblems by setting 
(x + 0.1666666667) equal to 0.299175823 and -0.299175823.

Subproblem 1

x + 0.1666666667 = 0.299175823 Simplifying x + 0.1666666667 = 0.299175823 Reorder the terms: 0.1666666667 + x = 0.299175823 Solving 0.1666666667 + x = 0.299175823 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.1666666667' to each side of the equation. 0.1666666667 + -0.1666666667 + x = 0.299175823 + -0.1666666667 Combine like terms: 0.1666666667 + -0.1666666667 = 0.0000000000 0.0000000000 + x = 0.299175823 + -0.1666666667 x = 0.299175823 + -0.1666666667 Combine like terms: 0.299175823 + -0.1666666667 = 0.1325091563 x = 0.1325091563 Simplifying x = 0.1325091563

Subproblem 2

x + 0.1666666667 = -0.299175823 Simplifying x + 0.1666666667 = -0.299175823 Reorder the terms: 0.1666666667 + x = -0.299175823 Solving 0.1666666667 + x = -0.299175823 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.1666666667' to each side of the equation. 0.1666666667 + -0.1666666667 + x = -0.299175823 + -0.1666666667 Combine like terms: 0.1666666667 + -0.1666666667 = 0.0000000000 0.0000000000 + x = -0.299175823 + -0.1666666667 x = -0.299175823 + -0.1666666667 Combine like terms: -0.299175823 + -0.1666666667 = -0.4658424897 x = -0.4658424897 Simplifying x = -0.4658424897

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.1325091563, -0.4658424897}

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