The inequality that represents Damon's catch is
20≤x≤26.
Since Jake caught 22 pounds, that means that together, Andy and Damon caught 56 pounds.
The lower limit for Andy is 30 pounds; if he caught this much, then Damon would have caught 56-30=26 pounds.
The upper limit for Andy is 36 pounds; if he caught this much, then Damon would have caught 56-36 = 20 pounds. This means that Damon's catch is between 20 and 26 pounds.