Applications
Problem 5
Answer 5
Step 1. Define the variables.
x = hours Jethro skateboards
y = hours Jethro walks
Step 2. Write an equation.
Since there are two rates, neither can be the slope alone.
The equation that describes this situation is: 7x + 3y = 6
Step 3. Substitute 0.5 for x and solve for y.
Jethro must walk 
of an hour.