Question

Roberto is having his house painted. The job takes three days, and he pays the painter the same hourly rate

Answer 1

Answer:

$\ 60\ per\ hour$

Step-by-step explanation:

we know that

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form $y/x=k$ or $y=kx$

In a proportional relationship the constant of proportionality k is equal to the slope m of the line and the line passes through the origin

Let

x -----> the number of hours worked

y ----> the amount paid in dollars

In this problem we have a proportional variation, between two variables, x, and y

Find out the constant of proportionality k

For (5,300) -----> $k=y/x$ ----> $k=300/5=60\ \ /h$

For (4,240) -----> $k=y/x$ ----> $k=240/4=60\ \ /h$

For (6,360) -----> $k=y/x$ ----> $k=360/6=60\ \ /h$

The constant k is

$k=60\ \ /h$

The equation is equal to

$y=60x$

The unit rate of change of dollars with respect to time is equal to the constant of proportionality or slope of the linear equation

therefore

$\ 60\ per\ hour$