If somebody could explain this to me I would really appreciate it. Grades are due today :))

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?

How to choose the sign of the radical in the denominator of the formula for the distance from a point to a line.

If you could answer these your a life saver