Question

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

(x2−1)(−2x+5)




say it like how a 8th grader would and easy to copy and paste for me...make it sound like I'm saying it

Answer 1

Okay, so let's look at the multiplication problem: (x² - 1)(-2x + 5). To show how multiplying polynomials is a closed system, I’ll break it down step by step.

1. **Distribute Each Term**: We need to distribute every term in the first polynomial (x² - 1) to every term in the second polynomial (-2x + 5).

2. **Multiply x² by Each Term**:
- First, multiply x² by -2x:
- x² * -2x = -2x³
- Now, multiply x² by 5:
- x² * 5 = 5x²

3. **Multiply -1 by Each Term**:
- First, multiply -1 by -2x:
- -1 * -2x = 2x
- Now, multiply -1 by 5:
- -1 * 5 = -5

4. **Combine All Results**: Now we combine everything we got from the distributions:
- So, we have: -2x³ + 5x² + 2x - 5

5. **Final Result**: The final expression we get is -2x³ + 5x² + 2x - 5. This is a polynomial.

Now, here’s why it’s a closed system: When we multiply two polynomials (like (x² - 1) and (-2x + 5)), the result is always another polynomial. This means we don’t get anything weird like a fraction or a radical, just another polynomial. So we can keep multiplying polynomials, and we’ll always end up with a polynomial. That shows that this system is closed!

And that’s how we do it! Easy peasy!