Lithium and magnesium bromide react to produce lithium bromide and magnesium metal

Explanation:

Single replacement reaction is a chemical reaction in which more reactive element displaces the less reactive element from its salt solution.

A more reactive element is one which can easily lose or gain electrons as compared to the other element.

The balanced chemical equation is:

Here Lithium being more reactive than magnesium, it can easily displace magnesium from its salt solution and form lithium bromide and magneium in elemental form.