1. The problem statement, all variables and given/known data The locus of z satisfying the inequality (z + 2 i) / (2 z + i) < 1 where z = (x + i y) 2. Relevant equations none 3. The attempt at a solution After putting the value of z = (x + i y) , I tried to rationalize it but now I am stuck. can somebody explain how to solve it. The correct answer is x2 + y2 < 1 Thank you in advance.