Answer:
[tex]y=4x[/tex]
Step-by-step explanation:
Let
y ----> the distance in miles
x ----> the time in hours
using proportion
[tex]\frac{y}{x}=\frac{(4/5)}{(1/5)}[/tex]
Simplify
[tex]\frac{y}{x}=\frac{4}{1}[/tex]
[tex]y=4x[/tex]
This is a linear direct variation
The unit rate or speed is the slope of the linear equation
The unit rate is 4 miles/hour