21x^2+24x-9=

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Solution for 21x^2+24x-9= equation:


Simplifying
21x2 + 24x + -9 = 0

Reorder the terms:
-9 + 24x + 21x2 = 0

Solving
-9 + 24x + 21x2 = 0

Solving for variable 'x'.

Factor out the Greatest Common Factor (GCF), '3'.
3(-3 + 8x + 7x2) = 0

Ignore the factor 3.

Subproblem 1

Set the factor '(-3 + 8x + 7x2)' equal to zero and attempt to solve: Simplifying -3 + 8x + 7x2 = 0 Solving -3 + 8x + 7x2 = 0 Begin completing the square. Divide all terms by 7 the coefficient of the squared term: Divide each side by '7'. -0.4285714286 + 1.142857143x + x2 = 0 Move the constant term to the right: Add '0.4285714286' to each side of the equation. -0.4285714286 + 1.142857143x + 0.4285714286 + x2 = 0 + 0.4285714286 Reorder the terms: -0.4285714286 + 0.4285714286 + 1.142857143x + x2 = 0 + 0.4285714286 Combine like terms: -0.4285714286 + 0.4285714286 = 0.0000000000 0.0000000000 + 1.142857143x + x2 = 0 + 0.4285714286 1.142857143x + x2 = 0 + 0.4285714286 Combine like terms: 0 + 0.4285714286 = 0.4285714286 1.142857143x + x2 = 0.4285714286 The x term is 1.142857143x. Take half its coefficient (0.5714285715). Square it (0.3265306123) and add it to both sides. Add '0.3265306123' to each side of the equation. 1.142857143x + 0.3265306123 + x2 = 0.4285714286 + 0.3265306123 Reorder the terms: 0.3265306123 + 1.142857143x + x2 = 0.4285714286 + 0.3265306123 Combine like terms: 0.4285714286 + 0.3265306123 = 0.7551020409 0.3265306123 + 1.142857143x + x2 = 0.7551020409 Factor a perfect square on the left side: (x + 0.5714285715)(x + 0.5714285715) = 0.7551020409 Calculate the square root of the right side: 0.868966076 Break this problem into two subproblems by setting (x + 0.5714285715) equal to 0.868966076 and -0.868966076.

Subproblem 1

x + 0.5714285715 = 0.868966076 Simplifying x + 0.5714285715 = 0.868966076 Reorder the terms: 0.5714285715 + x = 0.868966076 Solving 0.5714285715 + x = 0.868966076 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5714285715' to each side of the equation. 0.5714285715 + -0.5714285715 + x = 0.868966076 + -0.5714285715 Combine like terms: 0.5714285715 + -0.5714285715 = 0.0000000000 0.0000000000 + x = 0.868966076 + -0.5714285715 x = 0.868966076 + -0.5714285715 Combine like terms: 0.868966076 + -0.5714285715 = 0.2975375045 x = 0.2975375045 Simplifying x = 0.2975375045

Subproblem 2

x + 0.5714285715 = -0.868966076 Simplifying x + 0.5714285715 = -0.868966076 Reorder the terms: 0.5714285715 + x = -0.868966076 Solving 0.5714285715 + x = -0.868966076 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5714285715' to each side of the equation. 0.5714285715 + -0.5714285715 + x = -0.868966076 + -0.5714285715 Combine like terms: 0.5714285715 + -0.5714285715 = 0.0000000000 0.0000000000 + x = -0.868966076 + -0.5714285715 x = -0.868966076 + -0.5714285715 Combine like terms: -0.868966076 + -0.5714285715 = -1.4403946475 x = -1.4403946475 Simplifying x = -1.4403946475

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.2975375045, -1.4403946475}

Solution

x = {0.2975375045, -1.4403946475}

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