Mark B. answered • 11/28/17
Tutor
New to Wyzant
PhD Candidate in Psychology: Experienced Math, Statistics, Tutor
Good Morning, Hannah,
Personally, I would set this problem up like as a proportional equation because you are given three things here; speed of the car (on average and I am assuming this is a constant) the time (per hour) and the distance traveled (225 miles). What you are not given is the time it took to make that trip of 225 miles.
When setting up a proportional equation you want to make sure the same units or items of measure are on the numerator as well as the denominator. Please note: If I say that a car traveled at an average speed of 50 miles per hour, I am saying for every hour I travel, I am going 50 miles. Still a proportional equation assures you reach the correct conclusion.
Therefore:
50/1 = 225/x where x is the hours it took to make the trip.
You can now cross multiply.
Therefore:
50x = 225
Divide both sides of the equation by 50 because whatever you do on one side of an equation you must do on the other.
Therefore:
x = 225/50
x = 4.5
The great thing about using a proportional equation or any for that matter is you can check your work.
Remember our original equation?
50/1 = 225/x (where x is the time it took to make the trip) You now know the value of x, correct? It is 4.5
Therefore:
50/1 = 225/4.5 Cross multiply to check work.
50 * 4.5 = 225
225 = 225 Therefore, you have proven your work.
I wish you nothing but a great day at school and hope this helped.
Personally, I would set this problem up like as a proportional equation because you are given three things here; speed of the car (on average and I am assuming this is a constant) the time (per hour) and the distance traveled (225 miles). What you are not given is the time it took to make that trip of 225 miles.
When setting up a proportional equation you want to make sure the same units or items of measure are on the numerator as well as the denominator. Please note: If I say that a car traveled at an average speed of 50 miles per hour, I am saying for every hour I travel, I am going 50 miles. Still a proportional equation assures you reach the correct conclusion.
Therefore:
50/1 = 225/x where x is the hours it took to make the trip.
You can now cross multiply.
Therefore:
50x = 225
Divide both sides of the equation by 50 because whatever you do on one side of an equation you must do on the other.
Therefore:
x = 225/50
x = 4.5
The great thing about using a proportional equation or any for that matter is you can check your work.
Remember our original equation?
50/1 = 225/x (where x is the time it took to make the trip) You now know the value of x, correct? It is 4.5
Therefore:
50/1 = 225/4.5 Cross multiply to check work.
50 * 4.5 = 225
225 = 225 Therefore, you have proven your work.
I wish you nothing but a great day at school and hope this helped.
