Answer:
4 p and 10 O on both sides
Explanation:
on the reactant side you can see easily that there are 4 P. With the oxygen on the reactant side you take the coefficient (5) times the subscript (2) which gives a total of 10 Oxygens.
On the product side there is a subscript of 4 next to the p, and a subscript of 10 next to the O
They are equal on both sides so you are done.
