(3x^2+9x-7)-(12x^2-12x+4)=

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Solution for (3x^2+9x-7)-(12x^2-12x+4)= equation:


Simplifying
(3x2 + 9x + -7) + -1(12x2 + -12x + 4) = 0

Reorder the terms:
(-7 + 9x + 3x2) + -1(12x2 + -12x + 4) = 0

Remove parenthesis around (-7 + 9x + 3x2)
-7 + 9x + 3x2 + -1(12x2 + -12x + 4) = 0

Reorder the terms:
-7 + 9x + 3x2 + -1(4 + -12x + 12x2) = 0
-7 + 9x + 3x2 + (4 * -1 + -12x * -1 + 12x2 * -1) = 0
-7 + 9x + 3x2 + (-4 + 12x + -12x2) = 0

Reorder the terms:
-7 + -4 + 9x + 12x + 3x2 + -12x2 = 0

Combine like terms: -7 + -4 = -11
-11 + 9x + 12x + 3x2 + -12x2 = 0

Combine like terms: 9x + 12x = 21x
-11 + 21x + 3x2 + -12x2 = 0

Combine like terms: 3x2 + -12x2 = -9x2
-11 + 21x + -9x2 = 0

Solving
-11 + 21x + -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'.
1.222222222 + -2.333333333x + x2 = 0

Move the constant term to the right:

Add '-1.222222222' to each side of the equation.
1.222222222 + -2.333333333x + -1.222222222 + x2 = 0 + -1.222222222

Reorder the terms:
1.222222222 + -1.222222222 + -2.333333333x + x2 = 0 + -1.222222222

Combine like terms: 1.222222222 + -1.222222222 = 0.000000000
0.000000000 + -2.333333333x + x2 = 0 + -1.222222222
-2.333333333x + x2 = 0 + -1.222222222

Combine like terms: 0 + -1.222222222 = -1.222222222
-2.333333333x + x2 = -1.222222222

The x term is -2.333333333x.  Take half its coefficient (-1.166666667).
Square it (1.361111112) and add it to both sides.

Add '1.361111112' to each side of the equation.
-2.333333333x + 1.361111112 + x2 = -1.222222222 + 1.361111112

Reorder the terms:
1.361111112 + -2.333333333x + x2 = -1.222222222 + 1.361111112

Combine like terms: -1.222222222 + 1.361111112 = 0.13888889
1.361111112 + -2.333333333x + x2 = 0.13888889

Factor a perfect square on the left side:
(x + -1.166666667)(x + -1.166666667) = 0.13888889

Calculate the square root of the right side: 0.372677998

Break this problem into two subproblems by setting 
(x + -1.166666667) equal to 0.372677998 and -0.372677998.

Subproblem 1

x + -1.166666667 = 0.372677998 Simplifying x + -1.166666667 = 0.372677998 Reorder the terms: -1.166666667 + x = 0.372677998 Solving -1.166666667 + x = 0.372677998 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1.166666667' to each side of the equation. -1.166666667 + 1.166666667 + x = 0.372677998 + 1.166666667 Combine like terms: -1.166666667 + 1.166666667 = 0.000000000 0.000000000 + x = 0.372677998 + 1.166666667 x = 0.372677998 + 1.166666667 Combine like terms: 0.372677998 + 1.166666667 = 1.539344665 x = 1.539344665 Simplifying x = 1.539344665

Subproblem 2

x + -1.166666667 = -0.372677998 Simplifying x + -1.166666667 = -0.372677998 Reorder the terms: -1.166666667 + x = -0.372677998 Solving -1.166666667 + x = -0.372677998 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1.166666667' to each side of the equation. -1.166666667 + 1.166666667 + x = -0.372677998 + 1.166666667 Combine like terms: -1.166666667 + 1.166666667 = 0.000000000 0.000000000 + x = -0.372677998 + 1.166666667 x = -0.372677998 + 1.166666667 Combine like terms: -0.372677998 + 1.166666667 = 0.793988669 x = 0.793988669 Simplifying x = 0.793988669

Solution

The solution to the problem is based on the solutions from the subproblems. x = {1.539344665, 0.793988669}

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