So many confusing details. So, I rephrase the question as:
Four volunteers picked up litters from the park.
Dominic collect 15 pieces less than Sarah. Sarah collects 12 more pieces than Piper. Piper collected 1/4 as many pieces of letter as Vaughn. Vaughn has collected nine more pieces of letter than everyone else combined. Let x represent the number of pieces of litter in Vaughn's Collection. Find x
Answer:

Explanation:
Let:

From the [rephrased] question, we have:




Substitute
in




Make V the subject in


Substitute:
,
and
in


Collect like terms


Substitute
in



Substitute
in



Substitute
,
and
in



x represents the number collected by Vaughan.
So:
