## xokatexo 3 years ago Ian drives to town at 36 mph and returns at 48mph. If his total driving time is 3.5 hours, how far is he from town? Draw a diagram

1. Compassionate

Use the formula for distance: $d = r*t$

2. xokatexo

|dw:1348859120194:dw| Fill out the chart

3. CliffSedge

Assuming by, "returns," it means Ian is back at the original position, then you have one unknown distance, two known rates, and two unknown times that are related by t1+t2=3.5

4. CliffSedge

You can set up, initially, two independent equations with the unknowns 'd' and 't' and combine them (after making a substitution) into a single equation to solve for d.

5. CliffSedge

The instructions also ask for a diagram, so make sure you do that. Looking at a picture helps a lot to organized information.

6. xokatexo

|dw:1348859501586:dw| ???

7. CliffSedge

That's ok, but you can't have the same variable, x, for both unknown times. Try t for the first time and 3.5-t for the second time.

8. CliffSedge

That's not really a diagram - more of a chart or data table.

9. CliffSedge

Like I said, the two equations combine into a single one easily enough once you see how they are related.

10. CliffSedge

|dw:1348859649081:dw|

11. CliffSedge

That's close, but it's 3.5-x (x stands for time), not 35-x

12. CliffSedge

Yes, that's what you get when you set the two equations equal to each other (because the distance is the same).

13. CliffSedge

The two unknown variables are distance and time, but you can eliminate distance momentarily to solve for time, and then sub that back in to one of the first two equations to find the distance.

14. CliffSedge

OK. I am explaining the general way to solve these sorts of problems that works every time. If you want to do it another way and it works then that's fine.

15. CliffSedge

But just to let you know. '2' is not the correct answer.

16. xokatexo

well you didn't help at all and i mean x = 2...f you helped maybe id get the right answer..

17. CliffSedge

What about what I said do you think is not helping you? Do I need to explain the steps more clearly?

18. CliffSedge

If you want to know how to do these problems the right way and get the correct answer every time, I can help you, but if you are going to be rude and blow me off, then I wish you luck figuring it out on your own.

19. CliffSedge

In your equation, x does equal 2, but that does not answer the question...