If correct you get brainlest

Pls don’t use me for points

Area of bigger square : (side)²

Area of smaller square : (side)²

Area of shaded region is equal to :

that is :

hence, area of shaded region = 14x + 21

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