Answer:
He needs to make at least 5 more cookies but not more than 40
Explanation:
Walter needs to make at least 5 more cookies but no more than 40 cookies
20 ≤ x + 15 ≤ 55
Subtract 15 from all sides
20-15 ≤ x + 15-15 ≤ 55-15
5 ≤ x ≤ 40
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