Final answer:
To calculate Phil's net winnings from the poker tournament, subtract the cost of entering the tournament from the prize amount he received.
Step-by-step explanation:
To calculate Phil's net winnings from the tournament, we need to subtract the cost of entering the tournament from the prize amount he received. The expression for Phil's net winnings can be written as:
Net Winnings = Prize Amount - Cost to Enter
Given that Phil received a prize of xxx dollars and the tournament cost him 100100100 dollars to enter, the expression for Phil's net winnings is:
Net Winnings = xxx - 100100100