Yesterday, your checking account statement showed a balance of $17.Your friend paid back $30 today. What is your balance now?

The $30 your friend paid back will go into the checking account, so the balance will increase by that amount. Therefore, your balance will be $17 + $30 = $47.

from the sentence, "tomorrow morning, akiko will arrive an hour late" depicts a third person perspective because it doesn't use any pronoun to replace akiko, the subject of the sentence, and it is in singular form since akiko is only one person.

its line 2 i just added the rest or else it wouldn't let me answer