1. The problem is to create an equation using the digits 1 through 9 exactly once each, arranged to produce the highest possible integer value. 2. To maximize the integer value, we should arrange the digits in descending order from 9 to 1 to form the largest possible number. 3. The largest integer using digits 1-9 once each is simply the concatenation: $$987654321$$. 4. No operations are needed since the problem asks for the highest integer possible using each digit once. 5. Therefore, the answer is $$987654321$$, the largest 9-digit number with digits 1-9 used exactly once.