The area of a circle is pi times the radius squared (A = π r²).
You can you 72 which would make 2/8 18/72 and 3/9 24/72 which makes the sum 42/72.
The value for n is 
<h3>solving for n</h3>
<u>given data</u>
10n^{2} - 12 = -8
making n the subject of the formula
10n^{2} = -8 + 12
10n^{2} = 4
divide through by 10
n^{2} = 4 / 10
finding the square root of both sides
n = square root ( 4 / 10 )

n = 0.632 or 
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