It would tienes because it goes with tú. I'm not sure how to really explain it but that's the ser you would use with tú. I hope this helps!
Answer: Tenths.
Explanation: The place value of 2 in 84.265 is tenths because the number is right after the decimal point.
The answer to your question is read the text and write instructions to explain the last text. I may be wrong but was willing to answer. But can you explain the question a bit more please.?