If a precipitation reaction occurs when a solution of one species is added to a solution of the other, enter the formulas and states of all products. Separate by comma. If there is no reaction, enter the formula and state of all ions in solution.

magnesium chloride + silver nitrate →

I'll write the equation. You put it in the form required.

MgCl2(aq) + 2AgNO3(aq) ==> 2AgCl(s) + Mg(NO3)2(aq)
AgCl is a precipitate. The net ionic equation is
Ag^+(aq) + Cl^-(aq) ==> AgCl(s)