Question

CAN anyone help me on this i am so confused!

Mrs. Garney is planning a trip to Russia during the Christmas break. The flying distance from USA to Russia is 4900 miles. The flight information is shown on the TV on the flight. After 3 hours, the plane flew 500 miles. After 7 hours, the plane flew 1180 miles. Assume the plane has constant speed.
a) Write a linear equation to find the distance the plane traveled, where y is the distance traveled, and x is the number of hours.

Answer 1

a) Write a linear equation to find the distance the plane traveled, where y is the distance traveled, and x is the number of hours.

 
b) What is the average rate of change? What does it represent?
 
c) How much longer will Mrs. Garney need to stay on the plane until she reaches Russia?
Justify your answer with algebraic equation or a graph.

Answer 2

Lets name some variables before getting started

So y = distance traveled and x is number of hours

If it's going at a constant speed, then we can add both of the mile numbers they gave us and divide by 7.
Once you find that answer, then set up the equation as y = (Answer you got)(7), because the answer you got represents the speed of the plane. Try that and see what you get.

Answer 3

so im adding 500 miles and 1180 miles and dividing by 7?

Answer 4

i got 668.57142686

Answer 5

so that would be Y=668.57(7) right?

Answer 6

Yes. Doing that will get the constant speed.

You're linear equation is correct, but put an x instead of 7 (That's partly my fault for wording it), so it would be y = 668.57x

But it's not 668.57. Something was wrong with the math. Remember to add them both then divide that total by 7

Answer 7

ok i will try that :)

Answer 8

oh its 240
so it would be Y=240x

Answer 9

so what would i do for b and c?

Answer 10

The average rate of change is what you calculated earlier, 240mph.. I guess to explain it, you could say something simple like "The plane travels at a rate of 240 miles per 1 hour" or something like that.

For C, you need part A.

First, get the total distance, which is 4900 and subtract it from the number you found after adding 1180+500, so 4900 - (That number). That will get you how many miles she has left.

To find out how much longer she has, you would divide the answer you just got by 240, since the plane travels at 240 per hour.

So, (New answer)/240.. let me know what you get

Answer 11

i got 17.58 for my new answer is that correct?

Answer 12

and 4,220 miles

Answer 13

Remember when you got 240 in part A and added both the numbers? What did you get when adding them both? That's the number you subtract from 4900 to get now many miles you have left

Then after you subtract, take that number and divide by 240 to find the hours

Answer 14

i got 1680 then 3220

13.416

Answer 15

i realized my mistake i subtracted instead

Answer 16

Perfect!

Answer 17

thank you for helping me figure out how to do this! :)

Answer 18

Anytime!