Question 45593
x^2 - 2Rx + R^2 =0 This is a simple factoring job here
(x-R)(x-R)=0

when it comes to finding the zeros for this problem we have (x-R) twice so the answer is R with a multiplicity of 2  I don't know if this answer is beyond the scope of your class but this answer is complete.  Please let me know if you need further clarification