Week 4
Presentation:
Graphic Equations
Math 114N

The Problem:You are moving and need a rental truck. The rental company you have chosen charges a $70/day fee plus $0.20 for every mile you travel. Write a linear equation that expresses the total cost y, where x represents the number of miles you travel. Graph this equation. Then choose a number of miles, x, you travel that day and find the total cost of renting the truck.

The Linear Equation for problem
We have two numbers important to the
problem:
$.20 per mile
and
$70 per day
So we have Y representing the total it’ll
cost us. Thus making the equation
Y= .20x + 70

Finding the points
So we already know that the linear equation will be a
straight line. The reason for this is because nothing in the
equation is cubed or squared which will typically cause a
line to be curved.
For the first I will use: x=0
So 0 or the x place will represent
(the miles drove)
So when I plug 0 into the equation:
Y= .20x + 70
Y=.20(0)+70
Y=0+70
Y=70
Now the second: when x=1
So now I plug 1 for the miles
drove into the equation:
Y= .20x + 70
Y=.20(1)+70
Y=.20+70
Y=70.20

Now Lets Graph!
So previously we found our points
which are:
70 and 70.20
But we can’t plot points like this..
(0, 70 ) and (1, 70.20)
(0,70)
(1,70.20)