Answer:
985
Step-by-step explanation:
[tex]let\ m=6[/tex]
[tex]3^{6}=729[/tex][tex]999-729=270[/tex]
[tex]2^{8}=256[/tex] and [tex]2^{9}=512[/tex] which would be to big of a number.
[tex]3^{6}+2^{8}=729+256=985[/tex]
Therefore the largest three-digit integer in this system is 985