I need help with this idk what i am supposed to do

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?

25 ! the line of best fit is h = 5a + 86. predict the height at age 16. show your work.

What is the volume of a cone with a height of 6 cm in the radius of 2 cm