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Rates & proportional relationships: gas mileage

Maria and Nadia calculate their speed on a road trip to Toronto using distance and time. We compare different speeds using equations and tables. Then, we reinforce the concept by comparing the revolution speeds of records. Created by Sal Khan.

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• i still do not understand it how did he get 60mph from 4 hours and 240 miles.
• Think about how mph means "miles per hour" - you can write it in fraction form like this:

miles
-------
hour

Now, let's take the given information (4 hours & 240 miles) and plug the numbers into this fraction:

240 miles
------------- = 240 / 4 miles per hour = 60 mph
4 hours

Hope this helps!
• I get confused sometimes. Is the coefficient x, Or is the number 65 the coefficient? I find it difficult to tell which one is which sometimes, I just don't really understand or think that it makes very much sense.
• 65 is the coefficient (the number before the variable).
• wait a minute. . . I forgot how this works!! but I won't give up.
• Is the coefficient x or y
• Neither x nor y is the coefficient.
• I dont get it :,D?
• can you show me more about graphs
• I don't understand
• All in all it’s basically trying to compare rates. For that you can divide y by x, but there are also other ways. Depending on the exercise you compare.

For example:
Sarah is driving 340 miles in 5 hours. Andie is driving 153 miles in 3 hours. Who is driving faster?

Solution: Time is always considered as x and is always on the x-axis. Since you calculate y/x to be able to compare to rates or two of anything, you divide distance by time.
Sarah=m/h=340/5=68
Andie=m/h=153/3=51
Because 68 is greater than 51…
• What does revolution mean?
Please make it easy for me to understand^^;
thanks!
• It means how many times the disc spins around.
• i still do not understand it how did he get 60mph from 4 hours and 240 miles.