Okay
since the question said systems, this means we have to create more than just 1 equation for this we need to keep in mind that
1 nickel equals to 5 cents,
1n=5cents
which is the same as $0.05
also
1quarter equals 25 cents
1q=25cents
which is the same as $0.25
So, the system of equation would be the following:
where,
n is the number of nickels in his pocket, and
q the number of quarters