You multiply 4 by 3 because he got 4 stamps each week for 3 weeks. That leads to it being 12 stamps in total.
He wants 6 stamps out of 12 on each page of his album, so you divide 12 by 6 and get two.
He will use 2 pages.
The tools used were mathematical reasoning, multiplication and division.
With the given order of integration, the interval over D is

<h3>
Answer: 9.4 feet</h3>
Work Shown:
sin(angle) = opposite/hypotenuse
sin(22) = x/25
x = 25*sin(22)
x = 9.3651648353978
x = 9.4
Your calculator needs to be in degree mode. One way to check is to compute sin(30) and you should get 0.5 or 1/2.