The area of circle O is added to its diameter. If the circumference of circle O is then subtracted from this total, the result is 8. What is the radius of circle O?  Select the correct option: A) –2/pi B) 2 C) 3 D) 4 E) 5
pi*r^2 + 2r -2*pi*r = 8   Simplifying the equation: pi*r(r-2)+2r=8   Without much algebraic: We can Test the answers quickly, then 4 is the only possible answer that will eliminate pi from equation.   Answer is 4
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The area of circle O is added to its diameter. If the circumference of circle O is then subtracted from this total, the result is 8. What is the radius of circle O?