3x^2+12x-7=0

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Solution for 3x^2+12x-7=0 equation:


Simplifying
3x2 + 12x + -7 = 0

Reorder the terms:
-7 + 12x + 3x2 = 0

Solving
-7 + 12x + 3x2 = 0

Solving for variable 'x'.

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

Divide each side by '3'.
-2.333333333 + 4x + x2 = 0

Move the constant term to the right:

Add '2.333333333' to each side of the equation.
-2.333333333 + 4x + 2.333333333 + x2 = 0 + 2.333333333

Reorder the terms:
-2.333333333 + 2.333333333 + 4x + x2 = 0 + 2.333333333

Combine like terms: -2.333333333 + 2.333333333 = 0.000000000
0.000000000 + 4x + x2 = 0 + 2.333333333
4x + x2 = 0 + 2.333333333

Combine like terms: 0 + 2.333333333 = 2.333333333
4x + x2 = 2.333333333

The x term is 4x.  Take half its coefficient (2).
Square it (4) and add it to both sides.

Add '4' to each side of the equation.
4x + 4 + x2 = 2.333333333 + 4

Reorder the terms:
4 + 4x + x2 = 2.333333333 + 4

Combine like terms: 2.333333333 + 4 = 6.333333333
4 + 4x + x2 = 6.333333333

Factor a perfect square on the left side:
(x + 2)(x + 2) = 6.333333333

Calculate the square root of the right side: 2.516611478

Break this problem into two subproblems by setting 
(x + 2) equal to 2.516611478 and -2.516611478.

Subproblem 1

x + 2 = 2.516611478 Simplifying x + 2 = 2.516611478 Reorder the terms: 2 + x = 2.516611478 Solving 2 + x = 2.516611478 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-2' to each side of the equation. 2 + -2 + x = 2.516611478 + -2 Combine like terms: 2 + -2 = 0 0 + x = 2.516611478 + -2 x = 2.516611478 + -2 Combine like terms: 2.516611478 + -2 = 0.516611478 x = 0.516611478 Simplifying x = 0.516611478

Subproblem 2

x + 2 = -2.516611478 Simplifying x + 2 = -2.516611478 Reorder the terms: 2 + x = -2.516611478 Solving 2 + x = -2.516611478 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-2' to each side of the equation. 2 + -2 + x = -2.516611478 + -2 Combine like terms: 2 + -2 = 0 0 + x = -2.516611478 + -2 x = -2.516611478 + -2 Combine like terms: -2.516611478 + -2 = -4.516611478 x = -4.516611478 Simplifying x = -4.516611478

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.516611478, -4.516611478}

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