ok..so first write the charges on all the ions presnt.. bt remembr..only aqueous solutns tke chrges!!
so its:
3H+ 3NO3- (aq) + Al(OH)3 (s) --> 3H2O(l) + Al3+ 3NO3-(aq)
Then u cancel the spectator ions..i.e ions that repeat thmslves
so wat remains is:
3H+(aq)+Al(OH)3 (s) --> 3H2O(l) + Al3+(aq)