Answer:

Step-by-step explanation:
There are "2 parts" to the molecule S(NH₄)₂ 
- The ammonium (NH₄) 
- The sulfide (S)
Let's focus on the ammonium, since it contains the hydrogen. 
There is 1 Nitrogen atom (no subscript) and 4 hydrogen atoms ( subscript of 4).
But, this is only for 1 molecule of ammonium. If we look back at the original molecule, there is a subscript of 2 around (NH₄). This indicates there are 2 molecules of ammonium. 
There are 4 hydrogen atoms in 1 molecule. So, to find the number in 2 molecules, simply multiply 4 by 2. 
- 4 H atoms in 1 molecule * 2 molecules = 8 H atoms 
There are 8 hydrogen atoms in S(NH₄)₂