Answer:
Henry can download at most 225 MB more.
Step-by-step explanation:
The capacity of Henry's MP3 player is 512MB. He has downloaded 287MB and will continue to download m more megabytes.
Since the capacity of the player is 512MB. The used memory plus 287MB cannot be greater than 512MB, thus the inequality that shows how many more megabytes he can download are:
m + 287 ≤ 512
Solving:
m ≤ 512 - 287
m ≤ 225
Henry can download at most 225 MB more.