The area of Circle O is added to its diameter. If twice the circumference of Circle O is then subtracted from this total, the result is 8. What is the diameter of Circle O?
Answers
A) 4/π  B) 4  C) 8  D) 10  E) 6
area+diameter-2*circumference=8   pi*r^2+2r=8+2*2pi*r   isolate r and get r(pi*r+2)=8+4pi*r   r=(8+4pi*r)/(pi*r+2) =&gt;4(pi*r+2)/(pi*r+2)   r=4   Diameter = 2r = 8   8
<result>C</result>
The area of Circle O is added to its diameter. If twice the circumference of Circle O is then subtracted from this total, the result is 8. What is the diameter of Circle O?