Answer:
The radius is 8.5
Explanation:
Mathematically, the radius of a circle is the distance from the center of the circle to its circumference
Thus, as we have here;
The two marked lengths are radii of the inner inscribed circle and this means that they are equal in length
thus;
x + 6 = 5x-4
5x - x = 6 + 4
4x = 10
x = 10/4
x = 2.5
Now, to get the radius length, substitute the value of x in any of the lengths
from x + 6
2.5 + 6 = 8.5