Simplifying the Expression (-x-2)^3 + (2x-4)(x^2+2x+4) - x^2(x-6)
This article aims to guide you through the process of simplifying the given algebraic expression: (-x-2)^3 + (2x-4)(x^2+2x+4) - x^2(x-6). We will break down the problem into manageable steps and use fundamental algebraic rules.
Step 1: Expanding the Cubes and Products
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Expanding (-x-2)^3:
- Recall the cube of a binomial formula: (a+b)^3 = a^3 + 3a^2b + 3ab^2 + b^3
- Applying this to our expression, we get: (-x-2)^3 = (-x)^3 + 3(-x)^2(-2) + 3(-x)(-2)^2 + (-2)^3 = -x^3 + 6x^2 - 12x - 8
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Expanding (2x-4)(x^2+2x+4):
- This is a product of two binomials. We can expand it using the distributive property (FOIL method) or by recognizing it as a sum of cubes pattern.
- Let's use the sum of cubes pattern: (a-b)(a^2 + ab + b^2) = a^3 - b^3
- Applying this, we get: (2x-4)(x^2+2x+4) = (2x)^3 - (4)^3 = 8x^3 - 64
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Expanding -x^2(x-6):
- Simple distribution: -x^2(x-6) = -x^3 + 6x^2
Step 2: Combining Like Terms
Now, we have the expression: -x^3 + 6x^2 - 12x - 8 + 8x^3 - 64 - x^3 + 6x^2
Combine the like terms:
- x^3 terms: -x^3 + 8x^3 - x^3 = 6x^3
- x^2 terms: 6x^2 + 6x^2 = 12x^2
- x terms: -12x
- Constant terms: -8 - 64 = -72
Step 3: The Simplified Expression
Finally, combining all the simplified terms, we get the simplified expression:
6x^3 + 12x^2 - 12x - 72