To represent the amount of text messages \( m \) you can send given that each text message costs $0.15 and you can spend no more than $10, you can set up the following inequality:
\[ 0.15m \leq 10 \]
In this inequality, \( 0.15m \) represents the total cost of sending \( m \) messages, and this total cost must be less than or equal to $10.