Please help me, I am SO ticked off in my Algebra h-work??

Question

I've tried to get this answer, like, 20 times, and I do NOT get it. My dad's preoccupied w/ 2 or 3 football games and a race, so no help there, and so i really need your help.

In Exercises 64-66, you are running in a marathon. You either run 8 miles per hour or walk 4 miles per hour.

64. Write an equation to show the relationship between time run and time walked during the 26.2-mile course.

65. Graph the equation from Exercies 64. What are some possible running and walking times if you complete the 26.2-mile course?

66. If you walk for a total of 1 hour during the course, how long will you have spent running when you cross the finish line of the marathon?

Please help me. I'm ready to shred my math book and flush it in the toilet. I REEEEEEEEALLLY need help. Thanks.

btw, I know rate =distance x time. How do I plug that in?

Answer 1

OK

For 64, let x - mile you run per hour and let y be miles be walk per hour

8x + 4y = 26.2

For 65 I cannot show you the graph, but I can give you three or four points and you can graph it:

Points on the graph of the line above:

(0, 6.55) (3.275, 0) (2, 2.55) (2.275 ,2)

For 66, plug the one in the equation in 64:

8x + 4(1) = 26.2
8x + 4 = 26.2
8x = 22.2
x = 2.775 = 2 hours and 46.5

so total time = 1 + 2h 46.5 min = 3hrs 46.5 minutes.

Hope this helps!

Answer 2

64. Let x be the number of hours spent running
and y the number spent walking.
Now use your old standby d = rt and you get
8x + 4y = 26.2.
65. For the second part, just graph the intercepts
and plot a straight line.
If y = 0, x = 26.2/8 = 3.275
If x = 0, y = 26.2/4 = 6.55
What does this mean?
If you ran all the way, it would take 3.275 hours
or 3 hours, 16.5 min to complete the course.
If you walked all the way, it would take 6.55 hours
or 6 hours, 33 min to complete the course.
66. Now y = 1,
so 8x + 4 = 26.2
8x = 22.2
x = 2.775 or 2 hours 46.5 min.

No, don't shred your maths book yet! You'll
surely need it in the days to come!

Answer 3

There is one equation for this - distance = rate x time.
You have two variables, walking and running, and the rates for these, 4 and 8. You have the distance, 26.2 miles. The only thing you don't know is the time.
The distance from walking plus the distance from running is your total distance so your equation is 4(t1) +8(t2) =26.2.
As for your graph, the you'll need to graph distance versus time. The minimum time is if you ran the entire time; the maximum time is if you walked the entire time. Graph the two extremes and the area between is the possible times.
And as for 66, they're giving you t1 from the equation. Solve for t2.

People hate word problems, but don't have a problem if they're given the information. So the first thing you need to do is write down what you know and what you don't know. Once you have the information in a form you can recognize, figuring it out becomes much easier.

Answer 4

If you run for a total of r hours, and walk for a total of w hours, then you'll have travelled 8r by running and 4w by walking. The total trip is 26.2 miles, so 8r + 4w = 26.2

Pick whichever axis you want to be the "r" axis and the "w" axis, and graph the line from the equation.

Plug in w=1, and solve the equation for r.