Question

The sum of the areas of two circles is 80 pi square meters find the length of the radius of a radius of each circle if one of them is twice the orher

Answer 1

Let x=small circle
2x = bigger circle

πx^2 + π(2x)^2 = 80π
x^2 + 4x^2 = 80
5x^2 = 80
x^2 = 16
x = +/- 4
but we need the positive one because there's no negative measurement so
the answers are:
4m and 8m