Answer:
Step-by-step explanation:
Total for football: 9 +7
Total for figure skating: 12 +7
NEW Total for football: 16
NEW Total for figure skating: 19
The question says that 9 people like football
The question says that 12 people like to watch figure skating
The question also says that 7 people like to watch both, and because of that, you should add 7 to both 9 and 12, but keep the new numbers separated from each other. So once we know the sum of 9 +7 is 16, and 12 + 7 is 19, we can subtract the two numbers, and get 3 as the answer. Because you are counting the number of times that you have to travel up or down to the other number, and so if you are on a set of stairs that go up to the 16 level and you are on the 14th level, you need to travel up 2 sets of stairs to get to level 16.
Hope that example helps and can help in the future with other problems!
<span>The product of 718 and 82 is 58876. </span>
1.4km 1000 meters is equal to 1 kilometer
The two parabolas intersect for

and so the base of each solid is the set

The side length of each cross section that coincides with B is equal to the vertical distance between the two parabolas,
. But since -2 ≤ x ≤ 2, this reduces to
.
a. Square cross sections will contribute a volume of

where ∆x is the thickness of the section. Then the volume would be

where we take advantage of symmetry in the first line.
b. For a semicircle, the side length we found earlier corresponds to diameter. Each semicircular cross section will contribute a volume of

We end up with the same integral as before except for the leading constant:

Using the result of part (a), the volume is

c. An equilateral triangle with side length s has area √3/4 s², hence the volume of a given section is

and using the result of part (a) again, the volume is
