There is a rule in naming polyatomic anions containing oxygen.
Those names ending in <em>–ate</em> are given to the most common oxyanion of an element.
While those names ending in <em>–ite</em> are for those that contains fewer O atom for
the same charge. Since P has fewer O atoms, its name ends in <em>–ite</em>.
Thus, P is phosphite while P is phosphate.
The answer is (2) equal to. In redox reactions, you can't just lose electrons somewhere. If an electrons is lost by one, it must be gained by another. Hence, the importance of balancing redox reactions.