For this case we have that the area of a circle is given by:

Where:
r: It is the radius of the circle
By clearing the radio we have:

We take the positive value:

The diameter is twice the radius:

Answer:

Answer:
(y-(-2))/(x-(-1)= (-2-4)/(-1-3)
(y+2)/(x+1)= (-6)/(-4)
(y+2)/(x+1)= (3/2)
Cross multiplying
2y+4= 3x+3
3x-2y-1=0
Answer:
12
Step-by-step explanation:
36 divided but 3 is 12 so x=12
Answer:

Step-by-step explanation:
Let's solve this problem step-by-step. The library had 1,500 books in 2011. The ratio of books in 2011 and in 2012 is 1:2. Therefore, let the number of books in 2012 be
.
We have the following proportion:

Therefore, there were 3,000 books in 2012. The ratio of books in 2012 and in 2013 is 2:5. Let the number of books in 2013 be
.
We have:

Therefore, there were 7,500 books in 2013.
.19 thats the answer if you do the problem good luck<span />