9514 1404 393
Answer:
(a) 84
Explanation:
The largest integer that will round to 80 is one that does not have 5 or more in the ones place: 84.
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The largest decimal number of a particular precision is 84.99999... (some finite number of 9s). If there are an infinite number of 9s, the number can be shown to be equal to 85, which would round to 90.