Consider the hypothetical metallic element M, which is capable of forming stable simple cations that have charges of $1+, 2+,$ and $3+$ respectively. Consider also the nonmetallic elements $\mathrm{D}, \mathrm{E},$ and $\mathrm{F}$ , which form anions that have charges of $1-, 2-$ and $3-$ respectively. Write the formulas of all possible compounds between metal $\mathrm{M}$ and nonmetals $\mathrm{D}, \mathrm{E}$ , and $\mathrm{F}$ .