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Making Equations to Solve a Problem-HELP, PLEASE!

  1. Nov 18, 2008 #1
    Making Equations to Solve a Problem----HELP, PLEASE!

    1. The problem statement, all variables and given/known data

    Hi,

    I am in dire need of your help. I can't seem to solve this problem:

    Here's my trial on this:
    7h+11e= martians

    1/2(7h+11e) +1/2=295 eyes
    1/2 + 1/2(7h+11e)= 410 heads
    Then do the subtraction method from the linear equation to find one variable and go from there. The thing is I don't think my two equations are right because if I do that then all of the stuff on the left side will be 0 which is justly wrong.

    CAN ANYONE HELP ME GET THOSE TWO EQUATIONS PLEASE? I know that 7h+11e= martians though. I just don't know how to go further.


    Every little help counts. Please.



    ----------------------------------------------------------------
    ANOTHER QUESTION: (that I need help on)


    My tackle on this one:
    G= George's share of the money
    M= Martha's share of the money

    (3000+G) + (1/2M)=108,000
    G+M= 65,000

    I don't know if those equations are right. PLEASE HELP!

    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Nov 18, 2008 #2
    Re: Making Equations to Solve a Problem----HELP, PLEASE!

    for the first Q:

    You have martians described as 7h+11e (remember to define your variables... ie. let h be number of heads and let e be number of eyes, before you continue. Later on you'll find that e has a different meaning in mathematics and is rarely used as a variable)
    You have not, however described humans. What is the equation for a human (in terms of heads and eyes)?
    Then you may be able to continue with your simultaneous equations.

    Q2)
    I think you're on the right track, but: (again list define your variables)
    G+M=108000 (what they made last year together)
    G+3000+1/2M=65000 (what they made this year together)

    From this you can calculate what each made (last year) and then answer the rest of the question, ie. how much Martha got form other neighbours

    or

    G+M=65000 (what they made this year together)
    G-3000+2M=108000 (what they made last year together)

    From this you can calculate what each made (this year) and then answer the rest of the question, ie. how much Martha got form other neighbours

    Notice how it changes depending on how you define your variables!
     
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