Question

The difference of the areas of two circles is 21π. If their radii are r+3 and r, find the radius of the larger circle.

Answer 1

5

Answer 2

how u get?

Answer 3

pi(r+3)^2 - pi(r)^2 = 21 pi

Answer 4

r^2+6r+9-r^2=21
6r=21-9
6r=12
r=2
r+3=2+3=5
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