The rate a plumber charges is described by the function y = 21x + 45,

Question

where x is the number of hours worked and y is the total charge
The real-world meaning of the slope is

Answer 1

In the equation \( y = 21x + 45 \), the variable \( x \) represents the number of hours worked by the plumber, while \( y \) represents the total charge for the service.

The slope of the function, which is 21 in this case, represents the rate at which the plumber charges per hour of work. Specifically, the slope of 21 means that for each additional hour worked, the total charge increases by $21.

Additionally, the intercept (45) represents the base charge or fee that the plumber charges regardless of the number of hours worked. This fee could account for things like a call-out fee or a minimum service charge.

So, to summarize, the real-world meaning of the slope (21) is the hourly rate charged by the plumber.