Posted by Anna on .
Solve. Leave the answers in terms of pi ?.
a)Find a polynomial for the sum of the areas of the circles shown in the figure.
b)Find the sum of the areas when r = 5 and r = 11.3.
this is what I got but I did not do it right. I needed to To write an expression for the sum, i need to put everything together by adding the three terms that i wrote below but not sure how to start.
(pi*r2)+(pi*r2)
(pi*52)+(pi*11.32)
(25pi)+(127*69pi)
(152.69pi)
Large circle: A=pi*r2, Medium circle A=pi*32, Small circle A=pi*22

algebra 
Reiny,
Anna, I saw this post yesterday, and hoped you would realize that you can't post figures or pictures, so we can't see " the circles shown in the figure".
Do you have 2 separate circles, not overlapping ?
if so, then
for r=5 , area = π(5^2) = 25π
for r = 11.3, area = π(11.3^2) = 127.69π
so the total area = 25π + 127.69π = 152.69π
You seem to have that answer.
btw, to show exponents use the ^ key
e.g. 5^2 = 25