Answer:
To represent the distance Jon could have run any day this week, we can use the inequality:
\[ d \leq 3.5 \]
where \( d \) represents the distance Jon ran on any given day. This inequality states that the distance \( d \) must be less than or equal to 3.5 miles, which accounts for the fact that the most he ran in one day was 3.5 miles.