9514 1404 393
Answer:
2. 13√2
Explanation:
You can consider the radical as though it were some (non-numeric) symbol.
Using Ф for √2, this becomes ...
2Ф +4Ф +7Ф = (2+4+7)Ф = 13Ф
Using √2 for Ф, this becomes ...
= 13√2
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In short, do not be intimidated by the radical expression. Treat it as you would any other symbol for purposes of collecting terms. (Of course, you can only combine "like" radicals.)