Question

Finding Initial Value of Lessons
A graph has time (hours) on the x-axis and Total costs (dollars) on the y-axis. Points are at (4, 52), (5, 60), (6, 68) and (7, 76).

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

Let initial fee = b. Total cost = b + 8(hours).

Using (4, 52): b + 8(4) = 52 → b + 32 = 52 → b = 20.

The instructor’s initial charge is $20.