Amount of money charged by Luigi as fees = $140
Hourly rate of Luigi for each contract = $25
In the question there are more important informations already provided. Let us write them down first.
Total amount charged by Luigi for a project = y
Number of hours worked on the project by Luigi = x
Then the equation can be written as
y = 140 + 25x
The amount earned by Luigi after 10 hours = 140 + (25 * 10) dollars
= 140 + 250 dollars
= 390 dollars
So the amount earned by Luigi after 10 hours is $390.