Question

One bicyclist rides 4 mph more than another bicyclist. The faster rider takes 3 hours to complete a race, while the slower rider takes 4 hours. Find the speed of each rider.

Answer 1

Hint: This deals with having 4 added to an unknown number. Something like an "x" *hint hint*

Answer 2

d=rt

Answer 3

Can you get the equation setup or do you need help on that?

Answer 4

i always draw a small chart w/ all the distances, times, and speeds to help me keep track of it

Answer 5

I need help with the equation

Answer 6

Ok here's the equation explained:
You have Rider A and Rider B
Rider A travels at speed x.
Rider B travels at speed x+4mph.
Since they are both traveling at the same distance from equation of (Distance=Rate*Time) they are equal to each other.
So you have (x)mph*4 hours=(x+4)mph*3 hours
Just solve for 3 from here. :D

Answer 7

I meant "solve for x from here"

Answer 8

good explanation Firedude

Answer 9

Thanks :D, I'm just confused why the question is in the English system. Even here in the US we use the metric system in science.

Answer 10

I'm a little confused with how you solve.. do you divide both sides by x?

Answer 11

probably just for ease of the student. We see mph everyday.

Answer 12

??

Answer 13

Just try working one step at a time. Lets review the equation without the units and just the numbers and variables.
\[x*4=(x+4)*3\]
Now simplify the right side using the Distributive Property:
\[x*4=3x+12\]
Now get your like terms to one side:
\[4x-3x=12\]
Simplify:
\[x=12\]
Now since your x is just the speed from the beginning of Rider A (the slower rider)
You just solve for Rider B's speed since you know Rider A's speed (12mph).
Rider B was 4 mph faster than Rider A right? So its:
\[x=12\]
\[x+4mph\]
\[12+4mph=16mph\]
The faster rider goes 16mph while the slower rider goes 12mph. :D

Answer 14

Thanks so much, that really helped!

Answer 15

Glad to help!