Question

The graph shows the charges of an instructor. The instructor charges an initial fee and then an hourly rate of $8.00 an hour for private lessons. Determine the instructor’s initial charge from the graph.

Answer 1

Answer:

the real answer is $8.00 (D)

And the other one is also $20.00

Step-by-step explanation:

Answer 2

Answer:

The instructor’s initial charge is $20

see the attached figure

Step-by-step explanation:

Let

x ----> the time in hours

y ----> the total cost in dollars

we know that

The linear equation in slope intercept form is equal to

$y=mx+b$

where

m is the slope or the unit rate of the linear equation

b is the y-intercept or initial value (in this problem is the instructor’s initial charge)

we have

The slope is equal to the  hourly rate

so

$m=\ 8.00\ per\ hour$

substitute

$y=8.00x+b$

To find out the y-intercept join the given points in the graph and find out the value of y when the value of x is equal to zero

see the attached figure

The y-intercept is the point (0,20)

therefore

The instructor’s initial charge is $20

Verify

take any point on the graph

(5,60)

For x=5, y=60

substitute in the linear equation and solve for b

$60=8.00(5)+b$

$60=40+b$

$b=\ 20$ ----> is ok

therefore

The instructor’s initial charge is $20