Answer:
and 
Step-by-step explanation:
Let
x -----> the altitude of a commercial aircraft
we know that
The expression " A minimum altitude of 29,000 feet" is equal to

All real numbers greater than or equal to 29,000 ft
The expression " A maximum altitude of 41,000 feet" is equal to

All real numbers less than or equal to 41,000 ft
therefore
The compound inequality is equal to
and 
All real numbers greater than or equal to 29,000 ft and less than or equal to 41,000 ft
The solution is the interval ------> [29,000,41,000]