Maybe you should say that you find a solution on math.stackexchange.
Hi, I'm not sure how to go about finding the solution to this question.
Let R be a ring with identity such that x^{2} = 1_{R}for all 0_{R }=/= x in R. How many elements are in R?
I've just been playing around with squaring elements, like (x+1_{R})^{2} = x^{2}+2.x+1_{R} =2.x+2.1_{R} = 1_{R. }But I'm not sure where to go with this. Any help?