The function is , where A(t) represent the number of audio books and t represents the number of months.
Substitute the values of in the original function.
.
He will have 39 books after 8 months.
The solution is 39.
![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=fbc5bcc85f8168d88f4959f58fa4abde.png\")
, where A(t) represent the number of audio books and t represents the number of months.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=bbcee81141294851b015a35e01dd1d37.png\")
in the original function.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=777da67cdfab492c04ecafa9dd06ab13.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=e190b8ad6825ef409f59e180a1a6b468.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=a637806970c53471e927b0f2e3286460.png\")
.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")