Sue has 15-8 = <<15-8=7>>7 books left after returning at the library.
Sue returned 6/3 = <<6/3=2>>2 movies to the library.
Sue had 6-2 = <<6-2=4>>4 movies left.
Sue had 7+9 = <<7+9=16>>16 books after checking out at the library.
Sue has 16+4 = <<16+4=20>>20 movies and books combined.
#### 20