1. **Problem Statement:**
We have a polynomial $g(x)$ such that when divided by $(x+1)$, $(x-1)$, and $(x-2)$, the remainders are 1, $\frac{1}{2}$, and $\frac{2}{3}$ respectively.
We define $Q(x) = (x+3)g(x) - 2$ and need to show that $Q(x)$ is divisible by $(x+1)$, $(x-1)$, and $(x-2)$.
2. **Key Formula and Rules:**
- The Remainder Theorem states that the remainder when a polynomial $f(x)$ is divided by $(x-a)$ is $f(a)$.
- If $Q(x)$ is divisible by $(x-a)$, then $Q(a) = 0$.
3. **Using the Remainder Theorem on $g(x)$:**
- Since remainder when $g(x)$ is divided by $(x+1)$ is 1, we have $g(-1) = 1$.
- Since remainder when $g(x)$ is divided by $(x-1)$ is $\frac{1}{2}$, we have $g(1) = \frac{1}{2}$.
- Since remainder when $g(x)$ is divided by $(x-2)$ is $\frac{2}{3}$, we have $g(2) = \frac{2}{3}$.
4. **Evaluate $Q(x)$ at the roots of divisors:**
- Calculate $Q(-1) = (-1+3)g(-1) - 2 = 2 \times 1 - 2 = 0$.
- Calculate $Q(1) = (1+3)g(1) - 2 = 4 \times \frac{1}{2} - 2 = 2 - 2 = 0$.
- Calculate $Q(2) = (2+3)g(2) - 2 = 5 \times \frac{2}{3} - 2 = \frac{10}{3} - 2 = \frac{10}{3} - \frac{6}{3} = \frac{4}{3} \neq 0$.
5. **Re-examining the last step:**
The problem states $Q(x)$ is divisible by $(x+1)$, $(x-1)$, and $(x-2)$, so $Q(2)$ must be zero.
Check calculations:
$Q(2) = (2+3)g(2) - 2 = 5 \times \frac{2}{3} - 2 = \frac{10}{3} - 2 = \frac{10}{3} - \frac{6}{3} = \frac{4}{3}$ which is not zero.
This suggests a possible typo or misunderstanding in the problem statement or remainder values.
6. **Assuming the problem wants to show divisibility by $(x+1)$ and $(x-1)$ only:**
Since $Q(-1) = 0$ and $Q(1) = 0$, $Q(x)$ is divisible by $(x+1)$ and $(x-1)$.
7. **Conclusion:**
$Q(x)$ is divisible by $(x+1)$ and $(x-1)$ as shown by $Q(-1) = 0$ and $Q(1) = 0$.
If the problem requires divisibility by $(x-2)$ as well, the given remainder values or $Q(x)$ definition may need revision.
**Final answer:**
$$Q(-1) = 0, \quad Q(1) = 0, \quad Q(2) \neq 0,$$
so $Q(x)$ is divisible by $(x+1)$ and $(x-1)$ but not by $(x-2)$ with the given data.
Polynomial Divisibility 900217
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