Salt pH in Aqueous Solution

[Rachael_1H]

Can someone please explain this problem from the textbook to me, step by step?

12.65) Determine whether an aqueous solution of each of the following salts is basic, acidic, or neutral. Write a chemical equation to justify your answer.

A. KBr
B. AlCl3
C. Cu(NO3)2

I mainly am confused by why the answer key has that the equation for AlCl3 is:
Al(H2O)6 + H20 <----> Al(H2O)5OH + H3O

and the equation of Cu(NO3)2 is:
Cu(H2O)6 + H2O <----> H3O + Cu(H2O)5OH

[Chem_Mod]

Salts of metals are acidic because they will form metal hydroxides. Where does the hydroxide come from? It's ripped off of water, M + H2O --> M(OH) + H, resulting in protons in solution (acidic)