Can someone answer. there is one problem. there's a picture. you!

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?

What number should be added to the expression x^2+3x+ in order to create a perfect square trinomial? 3/2 3 9/4 9

What are the coordinates of the midpoint of ab? ,1/2) /2,-1) ,-3/2) /2,-2)