1. **State the problem:** Divide the polynomial $x^4 - 2x^3 - 4x + 5$ by $3x^3 + 2$.
2. **Set up the division:** We want to find the quotient $Q(x)$ and remainder $R(x)$ such that:
$$x^4 - 2x^3 - 4x + 5 = (3x^3 + 2)Q(x) + R(x)$$
where the degree of $R(x)$ is less than the degree of $3x^3 + 2$ (which is 3).
3. **Divide the leading terms:**
Divide $x^4$ by $3x^3$:
$$\frac{x^4}{3x^3} = \frac{1}{3}x$$
This is the first term of the quotient $Q(x)$.
4. **Multiply and subtract:**
Multiply $3x^3 + 2$ by $\frac{1}{3}x$:
$$\frac{1}{3}x \times (3x^3 + 2) = x^4 + \frac{2}{3}x$$
Subtract this from the dividend:
$$\left(x^4 - 2x^3 - 4x + 5\right) - \left(x^4 + \frac{2}{3}x\right) = -2x^3 - 4x + 5 - \frac{2}{3}x = -2x^3 - \left(4 + \frac{2}{3}\right)x + 5 = -2x^3 - \frac{14}{3}x + 5$$
5. **Repeat division with new polynomial:**
Divide the leading term $-2x^3$ by $3x^3$:
$$\frac{-2x^3}{3x^3} = -\frac{2}{3}$$
This is the next term of the quotient.
6. **Multiply and subtract again:**
Multiply $3x^3 + 2$ by $-\frac{2}{3}$:
$$-\frac{2}{3} \times (3x^3 + 2) = -2x^3 - \frac{4}{3}$$
Subtract this from the current polynomial:
$$\left(-2x^3 - \frac{14}{3}x + 5\right) - \left(-2x^3 - \frac{4}{3}\right) = -2x^3 - \frac{14}{3}x + 5 + 2x^3 + \frac{4}{3} = -\frac{14}{3}x + \left(5 + \frac{4}{3}\right) = -\frac{14}{3}x + \frac{19}{3}$$
7. **Check remainder degree:**
The remainder is $-\frac{14}{3}x + \frac{19}{3}$, which is degree 1, less than degree 3 of divisor, so division stops.
8. **Write final answer:**
$$Q(x) = \frac{1}{3}x - \frac{2}{3}, \quad R(x) = -\frac{14}{3}x + \frac{19}{3}$$
**Therefore,**
$$x^4 - 2x^3 - 4x + 5 = (3x^3 + 2)\left(\frac{1}{3}x - \frac{2}{3}\right) + \left(-\frac{14}{3}x + \frac{19}{3}\right)$$
Polynomial Division 56Ef62
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