If Sibyl has seen 4 more films than Linda, then Linda has seen 4 less films that Sibyl. So, you can write the expression L (Linda)=S-4.
If Linda has seen twice as many films as Joel, then Joel has seen half the films that Linda has seen. So you can write this at J=1/2L.
If L=s-4, then the number of films Joel has seen can be written as 1/2(s-4).
I hope this helps!
