(a) The integral is equal to the area of the triangle; it has height 20 and base 10, so the area is 20*10/2 = 100.
(b) The integral is equal to the area of the semicircle with radius 10. It's also under the horizontal axis, so the area is negative. The semicircle has area
, so the integral is -50π.
(c) First compute

which is the area of the triangle on the right. It has height and base 5, so its area is 25/2.
Then split up the desired integral as

and plug in the integral values you know:

When you're trying to find something in the simplest form, you have to find a common denominator. The best way to do this is to find the factors.
Factors of 3= 1, 3
Factors of 28= 1,2,4,7,14,28
In this case, the lowest factor is one, which is what they are currently in.
Therefore, 3/28 is currently in its simplest form
Answer:
1980
We can choose 2 men from 9 in 36 in ways.
We can choose 2 women from 11 in 55 ways.
For any arrangement of 2 men there are 55 ways of combining them with 2 women => 55 * 36 = 1980 total ways.
If you're wondering how i got the numbers i used the combination formula:
C(n, k) = 
Given:
Side length = 12 in
To find:
The area of the regular polygon.
Solution:
Number of sides (n) = 6
Let us find the apothem using formula:

where s is side length and n is number of sides.




Area of the regular polygon:




in²
The area of the regular polygon is 374.1 in².