(x+3)(x^2-3x+9)-x(x-2)(x+2)+11=0

2 min read Jun 16, 2024
(x+3)(x^2-3x+9)-x(x-2)(x+2)+11=0

Solving the Equation: (x+3)(x^2-3x+9)-x(x-2)(x+2)+11=0

This equation might look intimidating at first, but with a few algebraic manipulations, it can be solved. Let's break down the steps:

Step 1: Expand the Products

First, we need to expand the products in the equation using the distributive property and the difference of squares formula:

  • (x+3)(x^2-3x+9) This is a special product known as the sum of cubes: (a+b)(a^2-ab+b^2) = a^3 + b^3. Applying this, we get x^3 + 27.
  • x(x-2)(x+2) This is the product of a difference of squares: (a-b)(a+b) = a^2 - b^2. Expanding, we get x(x^2 - 4) = x^3 - 4x.

Step 2: Simplify the Equation

Now, substitute the expanded forms back into the original equation:

x^3 + 27 - (x^3 - 4x) + 11 = 0

Simplifying further:

x^3 + 27 - x^3 + 4x + 11 = 0

Combining like terms:

4x + 38 = 0

Step 3: Solve for x

Finally, we can solve for x by isolating it:

4x = -38

x = -38/4

x = -9.5

Conclusion

Therefore, the solution to the equation (x+3)(x^2-3x+9)-x(x-2)(x+2)+11=0 is x = -9.5.

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