Using the arrangements formula, it is found that he can line the books up on his bookshelf in 24 ways.
The number of possible arrangements of a set of n elements is given by the factorial of n, that is:
[tex]A_n = n![/tex]
In this problem, he is going to arrange 4 books(English, biology, history and health), hence [tex]n = 4[/tex] and:
[tex]A_4 = 4! = 24[/tex]
He can line the books up on his bookshelf in 24 ways.
A similar problem is given at https://brainly.com/question/24648661