Vector question: Explanation on “what to do to solve it?”
Question
Let the distance be called D.
D^2 = (x -1)^2 + (y – 1)^2 ..(1)
D^2 = (x -2)^2 + (y +1)^2 ….(2)
D^2 = (x +1)^2 + y ^2 ….(3)
3 equations and 3 unknowns… Solve it simulteneously and you are done.