To match the axes correctly, we have to combine both symbols and use the criss cross method.
For the second row:
[tex]\begin{gathered} Na^++OH^-\rightarrow NaOH \\ Na^++NO_3^-\rightarrow NaNO_3 \\ Na^++CO_3^{-2}\rightarrow Na_2CO_3 \\ Na^++SO_4^{-2}\rightarrow Na_2SO_4 \\ Na^++PO_4^{-3}\rightarrow Na_3PO_4 \end{gathered}[/tex]For the third row:
[tex]\begin{gathered} Mg^{+2}+OH^-\operatorname{\rightarrow}Mg(OH)_2 \\ Mg^{+2}+NO_3^-\operatorname{\rightarrow}Mg(NO_3)_2 \\ Mg^{+2}+CO_3^{-2}\rightarrow MgCO_3 \\ Mg^{+2}+SO_4^{-2}\rightarrow MgSO_4 \\ Mg^{+2}+PO_4^{-3}\rightarrow Mg_3(PO_4)_2 \end{gathered}[/tex]For the last row:
[tex]\begin{gathered} NH_4^++OH^-\operatorname{\rightarrow}NH_4OH \\ NH_4^++NO_3^-\rightarrow NH_4NO_3 \\ NH_4^++CO_3^{-2}\rightarrow(NH_4)_2CO_3 \\ NH_4^++SO_4^{-2}\rightarrow(NH_4)_2SO_4 \\ NH_4^++PO_4^{-3}\rightarrow(NH_4)_3PO_4 \end{gathered}[/tex]