Question

A jet ski company charges a flat fee of $24.00 plus $2.25 per hour to rent a jet ski. Another company charges a fee of $23.00 plus $2.75 per hour to rent the same jet ski.
Using a graphing calculator, find the number of hours for which the costs are the same. Round your answer to the nearest whole hour.

A) 2
B) 3
C) 4
D) 8

Answer 1

The advantage of the graphing calculator is that you just have to find two independent equations, introduce them in the calculator and it will find the intersection point ot the two graphs.

The equations that you have to introduce are:

1) y = 2.25x + 24

2) y = 2.75x + 23

The algebraic solution, which will give you the same coordinates of the intersection point of the graphs is

2.25x + 24 = 2.75x + 23

2.75x - 2.25x = 24 - 23

0.5x = 1 => x 1 /0.5 = 2.

Answer: 2