Answer:
a=8
c=5.5
Step-by-step explanation:
solve simultaneously:
2a + 4c = 38.00
3a + 3c = 40.50
times the first eq. by 3 and the second by 2
6a + 12c = 114
6a +6c = 81
subtract from one another
6a + 12c = 114
-6a +6c = 81
6c = 33
c=5.5
3a + 3x5.5 = 40.50
3a= 24
a=8
Answer: 
Step-by-step explanation:
The perimeter of a rectangle can be calcualated with this formula:

Where "l" is the lenght and "h" is the height.
The area of a rectangle can be found with this formula:

Where "l" is the lenght and "h" is the height.
In this case we know that:

Therfore, we can susbsitute them into
and solve for "h" in order to find its value:

Find two number whose sum is 3 and whose product is -40. These are -5 and 8. Then, factorizing, we get:

The positive value is the height. Then:

Since the length is 3 centimeters greater than its height, we get that this is: Then:

Substituting values into
, we get that the perimeter is:

Answer-
You can read 2 groups of three books.
Step-by-step expression-
3 times 3 is 9. Since 9 is bigger than 8, you multiply 3 by 2. 3 times 2 is 6. Therefore, you can only read 2 groups of 3 books. Happy studying :))
Below is a labeled rectangle:
length = w + 20
we know length is 36 so we plug that in:
36 = w + 20
We need to isolate w and to do that we must subtract 20 from both sides:
(36 - 20) = w + (20 - 20)
16 = w + 0
w = 16
width is 16 feet
Hope this helped!
Answer:
37.36%
Step-by-step explanation:
Each year it increases 1.6%.
So year 1 it increases (1+1.6%), year 2 increases (1+1.6%)^2 and so on...
so after 20 years, overall increase is found by 1.016^20 = 1.3736 or increase of 37.36%
please give thanks :)