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Math homework, HELPPPP`

Discussion in 'The Lounge' started by Capman2k, Jan 28, 2007.

  1. Capman2k

    Capman2k 3/4 ton status

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    I need to solve this: A circle has a circumference of 48(pi) inches. Find its radius.

    So my book has an example of how to figure out a circumference (C=2[pi]R) and I also have an example of how to find the area... But I don't need any of those things, I need the friggin radius....

    I'm not sure quite how to set it up, maybe 48(pi)=2(pi)R then solve for R????? :confused: :confused: :confused: em pleh
     
  2. ryan22re

    ryan22re 1/2 ton status

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  3. 1979jimmy350

    1979jimmy350 1/2 ton status

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    set it up like you said then solve for r you should get a answer of 24 inches
     
  4. Corey 78K5

    Corey 78K5 1 ton status

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    Real simple go out and buy a contractors calculator:thumb:
     
  5. Capman2k

    Capman2k 3/4 ton status

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    Good work, boyz thanks:D

    20 more problems to go, stand by
     
  6. cabledawg

    cabledawg Secret Squirrel Premium Member

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    Actually circumfrence is D x pi. So divide 48 by pi, then divide by 2 (radius is half of the diameter) and the answer should be 7.63 and some change. I use this all the time to find out how far a particular sized tire will travel in one revolution.
     
  7. enginenine

    enginenine Registered Member

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    circumference = Pi * 2 * radius. Work backwards
     
  8. colbystephens

    colbystephens 1 ton status GMOTM Winner

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    if you divide 48 (pi) by (pi) you get 48. then divide by two and you've got 24...
     
  9. Capman2k

    Capman2k 3/4 ton status

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    **** I hate math... I'm not finishing this assignment. If a math problem makes me swear and want to stab something I think that's enough homework for one day :rolleyes:

    Kay's change purse has nickels and dimes in it. The number of nickels is 5 more than twice the number of dimes. If the total value of the coins is $4.05, how many nickels are in the purse?

    I've spent 25 minutes on this one and no answer... Maybe I'm a retard, but I follow the example in the book and can't get an answer that could possibly be correct, the closest I've gotten is within .01 of an answer that could even POSSIBLY work... :mad:
     
  10. Resurrection_Joe

    Resurrection_Joe 1 ton status

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    19 Dimes

    43 Nickles












    405 - (5x5) = 380

    2X Nickles = 1X Dimes

    380/2 = Amount In Dimes And Nickles

    190 = 19 Dimes

    190 = 38 Nickels + 5 Nickles

    Blah Blah Blah

    Hooray for my ****ed up head!
     
  11. dhcomp

    dhcomp 3/4 ton status Premium Member

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    Set up eqns, n=5+2d
    5n+10d=4.05

    plug one into the other, solve. plug result into either, solve for other.
     
  12. CustomChevy

    CustomChevy 1/2 ton status

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    n = nickles
    d = dimes

    n = 2d + 5

    so if

    5n + 10d = 405

    sub in n
    5(2d + 5) + 10d = 405

    Compleat Multiplication
    10d + 25 + 10d = 405
    Subtract 25 from both sides
    10d + 10d = 380
    total d's
    20d = 380
    devide both sides by 20
    d = 19

    So if
    n = 2d + 5
    n = 2(19) + 5
    n = 38 + 5
    n = 43

    to check
    5 * 43 + 19 * 10 = 405
    215 + 190 = 405
     
  13. Capman2k

    Capman2k 3/4 ton status

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    Hrmmm... I'm not quite getting where y'all are getting 5 and 10 from.

    Wouldn't it be .05(2d+5) + .10d putting the values of the coins next to the variable that determines the number of coins? Then you'd multiply the value of each coin by the number of coins to get the amount of money...:confused:
     
  14. Capman2k

    Capman2k 3/4 ton status

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    Oh I see, you dropped the decimals... Got it... You guys are my heroes... Now if I could get a book that explains stuff better or an instructor that gives better lectures......
     

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