Answer:
D. 3√3 + √6
Step-by-step explanation:
We have to simply the following expression.
![\sqrt[]{6}+\sqrt[]{18}+3\sqrt[]{3}-3\sqrt[]{2}](https://img.qammunity.org/2023/formulas/mathematics/college/sls2fj7d27o9dv42rupy9iz63746me6y1w.png)
The expression contains four terms, one of which (√18) can be further simplified.
Now we can write √18 as
![\sqrt[]{18}=\sqrt[]{2\cdot9}](https://img.qammunity.org/2023/formulas/mathematics/college/ihmlslsdi24p0nru2oni7enjsc27r7rnuz.png)
![=\sqrt[]{9}\cdot\sqrt[]{2}](https://img.qammunity.org/2023/formulas/mathematics/college/877zcycouexmug3xioc1emakce3r0ogpcp.png)
since √9 = 3, the above becomes
![3\sqrt[]{2}](https://img.qammunity.org/2023/formulas/mathematics/high-school/4aqr9uynrzh3tgq2m7if5wqs351ynubeba.png)
Hence, our original expression becomes
![\begin{gathered} \sqrt[]{6}+\sqrt[]{18}+3\sqrt[]{3}-3\sqrt[]{2} \\ \Rightarrow\sqrt[]{6}+3\sqrt[]{2}+3\sqrt[]{3}-3\sqrt[]{2} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/nwavhnjs0u95g7pk2hpcsxma9uvjcn2vkn.png)
Now there are two 3√2 terms in the above expression, one negative and one positive. They cancel each other to give
![\begin{gathered} \sqrt[]{6}+3\sqrt[]{2}+3\sqrt[]{3}-3\sqrt[]{2} \\ \Rightarrow\boxed{\sqrt[]{6}+3\sqrt[]{3}} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/ajebuq3n86tk7pfm9r73rj2gu34e8ijoy5.png)
Hence, our original expression √6 + √18 + 3√2 - 3√2 is equivalent to
![\sqrt[]{6}+3\sqrt[]{3}](https://img.qammunity.org/2023/formulas/mathematics/college/j5gjw5mx7c8h30v2vbgsbbdo8o4gv0f21m.png)
Now looking at the answer choices we see that our expression matches choice D.
Therefore, choice D is the correct answer!