Erik is building a cubby bookshelf, that is, a book shelf divided into storage holes (cubbies) instead of shelves. He wants the height of the bookshelf to be x^2 - 6x - 27 and the width to be x^2 + 4x + 3. Each cubby hole in the bookshelf will have a height of x + 1 and width of x - 9. Step 1 of 3: Write a rational expression to determine how many cubbies high the book shelf will be. ​