Finding the molecular equation of this?

We have to find the molecular formula of Copper (II) sulfate and sodium phosphate. That would make it CuSO4 + Na3PO4. But when you switch the molecules the charges don't even out because Cu has a charge of 2+ and PO4 has a charge of 3-. What do you do to balance them out? Do the front numbers (I know they have a name but I don't remember)?