Posted by Cathy on .
The Goodyear Tire Company is testing a new tire. The tires are placed on a machine that can simulate the tires riding on a road. The machine is first set to 60 mph and the tires run at the speed for 7.2 hours. The machine is then set to a second speed and run at this speed for 6.8 hours. After this 14hour period,the machineindicated the tires have traveled the equivalent of 908 miles. Find the second speed to which the machine was set.
How do you determine how to set it up? I'm confused.

Algebra 2 
Kay,
let's say the second speed = x
look at how the units present in the q give you a clue about how to solve the equation:
*mph = miles per hour.
*hours.
*miles.
miles PER hour = miles/hour
MPH = miles/hour is the conversion
1. the first machine: 60mph and 7.2hours. how do you solve for miles?
miles=mph*hours
2. the second machine: set this one up, but use variable (x) for the speed (mph).
hope this helps 
Algebra 2 
carie,
45