Final answer:
The simplified form of the expression 2√2 - 7√18 is -19√2. This result does not match any of the answer choices provided, indicating a possible error in the options or question transcription.
Step-by-step explanation:
To simplify the expression 2√2 - 7√18, we first need to simplify √18. We can write √18 as √(9×2) which is the same as √9 × √2. Since √9 is 3, we have the expression √18 simplified to 3√2.
Now we substitute 3√2 back into the original expression:
Since both terms involve √2, we can combine them by subtracting their coefficients:
Therefore, the expression in simplified form is -19√2.
None of the given options OA 18√5, OB 84√2, OC 84, or OD 14√6 match our simplified result. It may be possible that there is a mistake in the options provided or in the transcription of the question.