5. A car travels at a speed of 72 miles per hour. Write a direct variation equation for the distance, y, the car will travel in x hours. How far will the car travels in 4.5 hours?

 y  = 72x

324miles

Step-by-step explanation:

Given parameters:

      Speed of the car = 72miles/hr

       distance  = y

        time  = xhrs

Unknown:

Write a direct variation equation for the distance=  ?

Distance covered in 4.5hrs =?

Solution:

A. Write a direct variation equation for the distance;

    A direct variation is a linear equation.

   It often takes the form y = kx

For this problem;

      Distance  = speed x time

input the parameters;

      y  = 72x

The direct variation equation is  y  = 72x

B. Distance traveled in 4.5hrs

   y  = 72x

  x is the time taken;

  So;

        y  = 72 x 4.5  = 324miles