Need help asap

[gkel7]

I am having trouble where to go with this question:
Amy travels 350 miles in her car at a certain speed. If the car had gone 20 MPH faster, the trip would have taken 2 hours less. Determine the speed of Amy's car. If necessary, round your answer to the nearest MPH.

 

[stapel]

I am having trouble where to go with this question:
Amy travels 350 miles in her car at a certain speed. If the car had gone 20 MPH faster, the trip would have taken 2 hours less. Determine the speed of Amy's car. If necessary, round your answer to the nearest MPH.

To learn the basics of setting up "uniform rate" exercises, try here. For instance, this link should clarify the thinking and method behind the first reply you received here, so you can do the same set-up procedure yourself on other, similar exercises:

actual trip:
. . .rate: r
. . .time: t
. . .distance d: 350 = rt

"if" trip:
. . .rate: r + 20
. . .time: t - 2
. . .distance: 350 = (r + 20)(t - 2)

I'd start by solving "350 = rt" for one of the variables, and then taking the result and plugging it into the second equation....

 

[HallsofIvy]

I am having trouble where to go with this question:
Amy travels 350 miles in her car at a certain speed.

Call the speed, in miles per hour, "v" and the time, in hours, "t". By the definition of (average) speed, v= 350/t.

If the car had gone 20 MPH faster, the trip would have taken 2 hours less. Determine the speed of Amy's car. If necessary, round your answer to the nearest MPH.

So if the speed were v+ 20, the time would be t- 2: v+ 2= 350/(t- 2).

Replace v in the second equation by 350/t and solve the resulting equation for t.