Answer:

Step-by-step explanation:
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
or 
In a proportional relationship the constant of proportionality k is equal to the slope m of the line and the line passes through the origin
Let
m ----> the distance in miles (y-coordinate)
h ----> the time in hours (x-coordinate)
In this problem the constant of proportionality k is given and is equal to
----> the speed
substitute

Substitution method can be applied in four steps
Step 1:
Solve one of the equations for either <span>x = </span>or y = .
Step 2:
Substitute the solution from step 1 into the other equation.
Step 3:
Solve this new equation.
Step 4:
Solve for the second variable.
hope this helps you!
PEMDAS
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction
Use these in order to get the correct answer.