Justin receives $15 $ 15 and puts it into his savings account. He adds $0.25 $ 0 . 25 to the account each day for a number of days, d , after that. He writes the expression 15+0.25(?1) 15 + 0 . 25 ( d - 1 ) to find the amount of money in his account after d days. Which statement about his expression is true?