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anonymous
 5 years ago
Please HELP! :)mr. Duncan traveled to a city 180 miles from him home to attend a meeting. Due to car trouble, his average speed returning was 13 miles less than his speed going. If the total time for the road trip was 7 hours, at what rate of speed did he travel to the city? (round to nearest tenth)
anonymous
 5 years ago
Please HELP! :)mr. Duncan traveled to a city 180 miles from him home to attend a meeting. Due to car trouble, his average speed returning was 13 miles less than his speed going. If the total time for the road trip was 7 hours, at what rate of speed did he travel to the city? (round to nearest tenth)

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anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Formula is d=rt. Make two equations and set them equal to each other to find the rate, and then find the average, which is the first plus the second divided by 2

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so 180=r7 so 173/2..so 86.5?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0distance equal rate x time there are two equations we can use here. Going and coming. let t= time going let 7t= time coming let x = rate going let x13 = rate coming distance going and coming is 90 (180/2) so remember d=rt coming 90 =(x13)(7t) going 90 = xt solve this system of equations.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0wait, did you just solve it? ha, i'm confused. That all kind of makes sense. I just am not sure what the last step is?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0@junwagh I think u r making a mistake The question says "Duncan traveled to a city 180 miles from his home" This means one way distance is 180 miles and not 90 miles

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I set up the problem. We set up two equations using d =rt. One for going and one for coming. Then you solve that system of equations. I won't do that for you, the hard part is setting up the equation. 90 = xt 90 = (x13)(7t)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0yep the total distance is 180

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0yes the total distance is 180, which means the distance going there is 90 and the distance coming back is also 90.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0oh wait mi bad lol replace 90with 180 then.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0The total distance has to be 360 miles as the "city is 180 miles from his house" so he has to go 180 miles and come back 180 miles

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0it says from his house to attend the meeting he drove 180 miles.. hmm yeah. you might be right. Ahh. does anyone have an answer. Now all the numbers are confusing me. want to make sure I know how to solve with the last steps

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0someone suggested 59 mph. anyone else get that?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Okay here is how u do it Let his speed while going = x miles /hour Then his speed while coming back = (x13) miles/hr Distance each side is 180 miles we know distance = speed x time or time = distance/speed So time taken while going = 180/x and time taken while coming back = 180/(x13)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Now the total time taken is 7 hours. This means (180/x) + 180/(x13) = 7 or 180(x13) + 180 (x)  = 7 x(x13) Simplifying the above we get 180x  2340 + 180x = 7 (x^2  13x)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so how do we find the rate of speed he traveled to the city Thank you for writing that all out for me. I just want to make sure I put in the correct answer.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0DOes anyone have a final answer for this problem? I have been trying to work it out for over an hour so I would really appreciate any help with the solution.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0what answer did you get?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Further this gives us 360x  2340 = 7x^2  91x Further simplifying we get 0 = 7x^2  91x  360x + 2340 or 7x^2  451x + 2340 = 0 This is a quadratic eqn. U can resolve it and get value of x

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0that got me 2 solutions. 5.69 and 58.74...Is there a way to make this into 1 answer?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0maybe i'll just try 58.74.. Think this will be right?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i got it right. THanks everyone

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.058.74 is correct as your speed cannot be 13 miles less than 5.69!!

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i actually did 58.7 and this was correct.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0It is a long winded question for sure

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0http://www.mathsisfun.com/quadraticequationsolver.html you can use that to solve your quadratic equation exactly. Just plug in your values.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0x=speed out, t=time out, x13=speed back, 7t=time back {x t == 180, (x13)*(7t)==180} {{x>5.69119,t>31.6278},{x>58.7374,t>3.06449}} Using second pair of x, y values. Speed, Time Out = {58.7374,3.06449} Speed, Time Back = {45.7374,3.93551}

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0@robtobey how did u get th values {{x>5.69119,t>31.6278},{x>58.7374,t>3.06449}}

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Running the Mathematica Solve function: Solve[ { x t == 180, (x13)*(7t)==180}, {x,t} ]

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0The syntax is somewhat weird. Those are, two consecutive = symbols.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I am not familiar with this... Anyway thanks for th reply!!

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0\[\left\{x\to \frac{1}{14} \left(451+\sqrt{137881}\right),t\to \frac{1}{26} \left(451\sqrt{137881}\right)\right\} \] The above is the actual output returned from Mathematica for the x, t, values used. Placing "//N" at the end converts to decimal numbers.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Is this Mathematica some program to calculate answer or is it a mathematical theory like quadratic equations etc The answer seems like solution to the quadratic eqn

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I calculated using the formula b + root b^2  4ac x =  2a

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Harkirat, mathematica is a mathematics software tool which helps you do calculations.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0OK!!??!! Thanks dhatraditya !! Is it free and available on net??

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Mathematica is a very large application system. About 3Gb of data to install it. It has been years in development and is mathematically very comprehensive in scope. It is about $2500 to a the common mom and popper who belly up to the cash counter to buy. For students and teachers they almost give it away. On the order of $125 one time cost as long as the student remains a student. The teachers probably would not allow it to be used in a class test but it will always show the correct answers for home work as long as the input is correct. If you give me a minute I'll find their web site.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0The Mathematica site is: http://www.wolfram.com/ I just purchasee Mathematica version 8 Home edition. It cost me about $280 for a box edition delivered to California. By the way the installation comes on a DVD not a CD. Because of low price, the use of the Home is very restricted. For instance I can not use in to make any money.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Thanks robtobey, I am in India and this is beyond my reach

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0They may ship to India or have an agent there. I have to break off now. Been good talking to you. Adios.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0thank friend n bye till we chat again
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