(Please see the question in the image) All coefficients that are number two are wrong answers and need to be replaced.

The balanced equation is:
[tex]2\text{NaN}_{3_{}\text{ }}\text{ }\rightarrow3N_2\text{ + 2Na}[/tex]The equation is balanced because we have the same amount of elements in the reactants side (to the left of the arrow) and in the products side (to the right of the arrow).