Question

John can send up to 250messages each month. So far he has sent 141 messages this month let t represent the number of messages he can send for the rest of the month

Answer 1

$141+t \leq 250$

The phrase "up to" means less than or equal to since John cannot send more than 250 messages. 

Answer 2

Here is the inequality:
t+141≤250
t≤109 messages. Hope it help!