walter needs to make at least 5 more cookies but no more than 40. 5 ≤ x ≤ 40
step-by-step explanation:
20 ≤ x + 15 ≤ 55
subtract 15 from all parts
20-15 ≤ x + 15-15 ≤ 55-15
5 ≤ x ≤ 40
this means how many more cookies he has to make
walter needs to make at least 5 more cookies, but no more than 40 cookies; 5 ≤ x ≤ 40