Will mark brainliest ! 12 points ! let b(t) be the number of unread books remaining on alex's bookshelf after reading consistently for t months. b ( t ) = 75 - 5t so, b ( 9 ) = . options : 70 or 30 or 45 or 15 this means that , options : * after 9 days * after reading 9 books per month * after reading 9 books * after 9 months the . options : * number of months that have passed is 70 * number of unread books remaining is 30 * number of unread books remaining is 45 * number of months that have passed is 15