pLease help me to find Ionic and net ionic equation?

[cutie angel]

A) HBr (aq) + NH3 (aq) ----> ?

B) Ba(OH)2 (aq) + H3PO4 -----> ?

C) HClO4 (aq) + Mg(OH)2 (s) -----.> Mg(ClO)2 + H2O not sure