Ok so the question is supposing that a,b are in Group G, the problem doesn't state that the group is cyclic or anything. But a,b in G and a has an odd order. then if

aba-1 = b-1 then b^2 = e. I did it at first but unfortunately I assumed the group is commutative which it isn't. Any hints on how to solve it if its not commutative. I was trying multiplying both sides of the equation by a, but I'm not getting anywhere, and am in desperate need of ideas. Thanks!!