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A simple problem for Grade 11

  1. Sep 28, 2005 #1
    I have a question, a huge one but simply it is.. A family goes on a ten hour drive, 100km an hour on highways(x) and 60km(y) an hour on city roads.
    100x+60y+880, and
    x+y=10

    Just need a push in the right direction. Thanks in advance.
     
  2. jcsd
  3. Sep 28, 2005 #2
    By the way, I have to find the hours in which they drove on each road type.
     
  4. Sep 28, 2005 #3
    what is the question?
     
  5. Sep 28, 2005 #4

    hotvette

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    Homework Helper

    Did you really mean 100x+60y=880? If so, what you have are 2 equations in 2 unknowns. Have you covered how to solve these types of problems?
     
  6. Sep 28, 2005 #5
    The bastow family drove to visit relatives. They drove a total of 880km in 10 hours. Their average speed was 100km on highways and 60km in the city. Let the time travelling on highways be "x" hours and the time on city roads be "y" hours. An equation that represents the total difference travelled is 100x+60y=880. An equation that represents the total travelling time is x+y=10.
    a) What time was spent travelling highways?
    b) What time was spent travelling city roads?
     
  7. Sep 28, 2005 #6
    yah, 100x+60y=880, sorry about that.
     
  8. Sep 28, 2005 #7
    We were taught substitution.
     
  9. Sep 28, 2005 #8

    hotvette

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    There you go!
     
  10. Sep 28, 2005 #9
    i dont exactly remeber you could try it this way tho
    take the second equation multipy iy by 100 so that x will be it will be 100x+100y=1000 put that direclty below the second equation subtract u will be left with 0 for the x then solve for y then plug y abck into the equation

    sumone correct me if im wrong cuz im not sure if it works for that type of problem but i use that in geometry.
    you cna alwyas try and cehck the answers in the book
     
  11. Sep 28, 2005 #10
    Oh man, jeeze, I can't believe I forgot that, thanks so much! :) You've both helped a heck of a lot!
     
  12. Sep 28, 2005 #11
    The final answer is (3,7)
     
  13. Sep 28, 2005 #12
    i cant help but feel that i ahve made a difference in sumone elses life today
     
  14. Sep 28, 2005 #13
    lmao, you sure have:D
     
  15. Sep 28, 2005 #14
    I'll pass the favor on tommorow:) Keep the chain going.
     
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