Calcium carbonate and hydrogen phosphate producing calcium phosphate, carbon dioxide, and water
Most likely that your teacher meant to say phosphoric acid ($\ce{H3PO4}$) rather than the hydrogen phosphate anion ($\ce{HPO4^{2-}}$) so lets go with that.

$$\ce{ 3CaCO3 + 2H3PO4 -&gt; Ca3(PO4)2 + 3CO2 + 3H2O}$$ 

In reality the carbon dioxide and water would exist in an equilibrium state with carbonic acid, $\ce{H2CO3}$:

$$\ce{ H2CO3 (aq) &lt;=&gt; H2O (l) + CO2(aq)}$$