1. Solving Rational Equations by
Graphing

2. Let’s do an example together.
A cyclist travels 10 miles in the same time that a walker travels 4 miles. The speed of the cyclist is 6 miles more than the speed of the walker. Find the speed of the cyclist and the walker.

3. How do you represent the walker’s and the cyclist’s speed?
Let x = walker’s speed
Let x+6 = cyclist’s speed

4. Remember to use the formula d=rt.
Walker
Cyclist =
Solve for t

5. Using your graphing calculator, graph the functions and find the intersection.

6. Using the x-coordinate of the positive intersection point, you find the answer.
Why use the positive x-coordinate?
What were the respective speeds of the cyclist and the walker?
The cyclist speed was 10 mph.
The walker’s speed was 4 mph.

7. Try this on your own.
A car travels 450 miles in the same time that a freight truck travels 250 miles. The speed of the car is 20 mph more than the truck’s speed. Find the speed of the truck and the car.
Car = 45 mph ; Truck = 25 mph