Balance the following equations:

a$.$

$Mn{O}_4^{-}+C_2{O}_4^{2-}longrightarrowM{n}^{2+}+C{O}_2$

b$.$

$N{O}_2^{-}+Mn{O}_4^{-}longrightarrowN{O}_3^{-}+M{n}^{2+}($in acid solution

c$.$

$I^{-}+Mn{O}_4^{-}longrightarrow{I}_2+Mn{O}_2$

$($in basic solution$)$

d$.$

$P+C{u}^{2+}$longrightarrowCu$+H_{2}P{O}_4^{-}$

e$.$

$Mn{O}_4^{-}+F{e}^{2+}longrightarrowM{n}^{2+}+F{e}^{3+}$

Determine the oxidation number of the atom accompanying the