Prove that the quadratic residues of 11 are 1,3,4,5,9, and list all solutions of each of the ten congruences

and where a=1,3,4,5,9.

i used Legendre to show (1/11)=1,...,(9/11)=1, for i used legendre again to show a=1,3,4,5,9 are quadratic residues of .

My problem is with the second part have no idea how to even begin.