Answer:
[tex]\$(10-p)[/tex]
Step-by-step explanation:
Nicholas used a $10 bill to pay for a granola bar that only costs p dollars.
To find much change Nicholas received, simply subtract the cost of granola bar from the amount of money Nicholas paid:
[tex]\$(10-p)[/tex]
For example, if granola bar costs p=$4, then Nicholas gets
[tex]\$(10-4)=\$6[/tex]
as a change.