Question

Use the following multiplication problem to show how multiplying polynomials is a closed system...

(x^2−1)(−2x+5)

Answers

Answer
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Answered by GPT-4o mini
To show that multiplying polynomials is a closed system, we will perform the multiplication of the polynomials \((x^2 - 1)\) and \((-2x + 5)\) and demonstrate that the result is also a polynomial.

Let's multiply the two polynomials step by step:

### Step 1: Apply the Distributive Property (FOIL)
We will distribute each term in the first polynomial to each term in the second polynomial:

\[
(x^2 - 1)(-2x + 5) = x^2 \cdot (-2x) + x^2 \cdot 5 + (-1) \cdot (-2x) + (-1) \cdot 5
\]

### Step 2: Calculate Each Term
Now, let’s compute each of these products:

1. \(x^2 \cdot (-2x) = -2x^3\)
2. \(x^2 \cdot 5 = 5x^2\)
3. \((-1) \cdot (-2x) = 2x\)
4. \((-1) \cdot 5 = -5\)

### Step 3: Combine All the Terms
Now combine all these results:

\[
-2x^3 + 5x^2 + 2x - 5
\]

### Result
The multiplication of \((x^2 - 1)\) and \((-2x + 5)\) results in:

\[
-2x^3 + 5x^2 + 2x - 5
\]

### Conclusion
The result \(-2x^3 + 5x^2 + 2x - 5\) is clearly a polynomial.

This demonstrates that the system is closed under multiplication, as the product of two polynomials is itself a polynomial. Thus, multiplying polynomials does not produce an outcome outside the set of polynomials, confirming the closure property of polynomial multiplication.
Answered by GPT-4o mini
To show that multiplying polynomials is a closed system, let's multiply the polynomials \( (x^2 - 1) \) and \( (-2x + 5) \).

### Step 1: Distribute Each Term
Using the distributive property:

\[
(x^2 - 1)(-2x + 5) = x^2 \cdot (-2x) + x^2 \cdot 5 + (-1) \cdot (-2x) + (-1) \cdot 5
\]

### Step 2: Calculate Each Product
1. \( x^2 \cdot (-2x) = -2x^3 \)
2. \( x^2 \cdot 5 = 5x^2 \)
3. \( (-1) \cdot (-2x) = 2x \)
4. \( (-1) \cdot 5 = -5 \)

### Step 3: Combine Results
Combining all terms:

\[
-2x^3 + 5x^2 + 2x - 5
\]

### Conclusion
The result, \(-2x^3 + 5x^2 + 2x - 5\), is a polynomial, demonstrating that the multiplication of polynomials is closed under this operation.

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