The equation y = 55x + 85 describes the amount of money a plumber charges, where y is the total amount he charges and x is the number of hours he works.

The equation y = 55x + 85 represents the relationship between the total amount of money a plumber charges (y) and the number of hours he works (x). This equation is in the form of a linear equation, which means that the relationship between the variables can be represented by a straight line on a graph.

To understand this equation, let's break it down:

- The coefficient of x, which is 55, represents the hourly rate the plumber charges. In this case, the plumber charges $55 per hour.
- The constant term, which is 85, represents the fixed amount that the plumber charges regardless of the number of hours worked. This could be a service fee or any other additional charge.

To calculate the total amount the plumber charges for a given number of hours, you simply need to substitute the value of x into the equation and solve for y. For example, if the plumber works for 3 hours, you can calculate the total amount charged by substituting x = 3 into the equation:

y = 55(3) + 85
y = 165 + 85
y = 250

So, if the plumber works for 3 hours, the total amount charged would be $250.