To represent the scenario mathematically, we can create an equation based on the information provided:
The total cost \( y \) includes two components:
- A service call fee of $135.
- A charge of $45.99 per hour for \( x \) hours of service.
The equation can be written as:
\[ y = 45.99x + 135 \]
In this equation:
- \( y \) is the total cost,
- \( x \) is the number of hours the plumber is at Zack's house,
- \( 45.99x \) represents the cost for the hours worked,
- and \( 135 \) is the fixed service call fee.