Student or Learner
I'll try to speak as slowly and as carefully as possible.
I'll try to speak as slowly and carefully as possible.
Are both good?
Repeating the "as" tends to indicate that the two adverbs are not particularly in concert.
Omitting the second "as" tends to "group" the two adverbs into one package, so that they are one and the same thing: a "slow careful" thing.
He ran up the stairs as quietly -- and as rapidly -- as he could.
In this case, the second "as" seems useful because "quietly" is not really part and parcel with "rapidly."
He ran up the stairs as slowly and quietly as he could.
This omission of the second "as" seems useful because "slowly" and "quietly" are being grouped as one basic approach.
This is like the difference between repeating the word "the."
1) The husband and wife came in to buy a car.
The omission of the second "the" before "wife" tends to group the two people into a team that is acting in concert:
The "husband and wife team" came in to buy a car.
But you would add "the" if you were conscious of their separateness.
The husband and the wife wanted two different models.