Polynomial Factorization Division F339E1
1. **Problem 1:** Factorize the cubic polynomial $x^3 - 13x^2 + 24x + 108$ given that one factor is $(x + 2)$. We want to find the other two factors.
2. Use polynomial division or synthetic division to divide $x^3 - 13x^2 + 24x + 108$ by $(x + 2)$.
3. Dividing, we get quotient $x^2 - 15x + 54$.
4. Now factor $x^2 - 15x + 54$. Find two numbers that multiply to $54$ and add to $-15$: these are $-6$ and $-9$.
5. So, $x^2 - 15x + 54 = (x - 6)(x - 9)$.
6. Therefore, the full factorization is:
$$x^3 - 13x^2 + 24x + 108 = (x + 2)(x - 6)(x - 9)$$
---
1. **Problem 2:** Perform polynomial division of $x^4 + 3x^3 + 2x^2 - 9x + 6$ by $x + 3$.
2. Use long division:
- Divide $x^4$ by $x$ to get $x^3$.
- Multiply $(x + 3)(x^3) = x^4 + 3x^3$.
- Subtract: $(x^4 + 3x^3) - (x^4 + 3x^3) = 0$.
- Bring down $2x^2$.
- Divide $2x^2$ by $x$ to get $2x$.
- Multiply $(x + 3)(2x) = 2x^2 + 6x$.
- Subtract: $(2x^2 - 9x) - (2x^2 + 6x) = -15x$.
- Bring down $+6$.
- Divide $-15x$ by $x$ to get $-15$.
- Multiply $(x + 3)(-15) = -15x - 45$.
- Subtract: $(-15x + 6) - (-15x - 45) = 51$.
3. The quotient is $x^3 + 2x - 15$ with remainder $51$.
4. So,
$$\frac{x^4 + 3x^3 + 2x^2 - 9x + 6}{x + 3} = x^3 + 2x - 15 + \frac{51}{x + 3}$$
---
**Final answers:**
- Factorization: $(x + 2)(x - 6)(x - 9)$
- Polynomial division quotient: $x^3 + 2x - 15$ with remainder $51$