Question

What is the overall equation for this chemical reaction?

Answer 1

We combine the two equations, like we would any mathematical system of equations. After addition of the two equations, we get:
Mg + 2H⁺(aq) + 2e⁻ → Mg⁺²(aq) + H₂(g) + 2e⁻
Cancelling like terms from both sides

Mg + 2H⁺(aq) → Mg⁺²(aq) + H₂(g)