Help Please!! Struggling with this for a while

12. the amount of money in a bank account decreased by 21.5% over the last year. if the amount of money at the beginning of the year is represented by ‘n', write 3 equivalent expressions to represent the amount of money in the bank account after the decrease?

Is a positive integer raised to a negative power always positive

Graham’s monthly bank statement showed the following deposits and withdrawals. -$25.20, $42.75, -$22.04, -$18.50, $74.11. part a if grahams baldness in the account was $37.86 at the beginning of the month,! 27/4! 2// the account balance at the end of the month? ? plz i will give you 100 points