<h3>
Answer: 18pi</h3>
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Explanation:
The area 81pi square meters leads to the radius 9 meters
Use the formula A = pi*r^2 to see why this is the case. You plug in A = 81pi and solve for r to get r = 9.
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Once you know the radius, you can determine the circumference C
C = 2*pi*r
C = 2*pi*9
C = 2*9*pi
C = 18pi
The circumference is the perimeter, or distance, around the circle.
The 1:3 ratio means that the distance from A to the point is 1/4 of the distance from A to B.
The difference of y-coordinates is 10-8 = 2. 1/4 of that is 2·1/4 = 1/2, so the point of interest will have y-coordinate 8 + 1/2 = 8 1/2. This apparently corresponds to the first selection:
... (6 1/2, 8 1/2)
First, we want to find the GCF of 15 and 21, which is 3. Now we do 15 divided by 3 and 21 divided by 3, which gives us 5 and 7. To rewrite the expression, we take the GCF and put it on the outside of the parenthesis. Inside the parenthesis, we put 5 + 7. So it'll look like this:
3(5 + 7)
What you do here is subtract g from f: x^2 - 5x + 8 - (x^2 -4); x^2 - 5x + 8 - x^2 + 4; Rearranging gives you x^2 - x^2 - 5x + 8 + 4 which is, simplified, -5x + 12
