Scalar multiplication of an expression containing equality [duplicate]

Suppose:

expr=(a x + a y==0);
expr/a
(*Out:=(a x + a y==0)/a*)


I want a eliminated to obtain expr=(x+y==0). None of Expand, Simplify, FullSimplify work. Any suggestions?

Use Thread[]:
expr = a x + a y == 0;

• +1 Thanks. I also found another way: Assuming[a != 0, Simplify[expr]] – Deep Oct 1 '17 at 12:57