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System of 2 equations

  1. Jan 16, 2017 #1
    1. The problem statement, all variables and given/known data

    It's a system of 2 equations.

    upload_2017-1-16_14-4-4.png
    upload_2017-1-16_14-4-10.png

    2. Relevant equations


    3. The attempt at a solution
    My attempt is not worth writing here.
    Results I got using Microsoft Mathematics without showing me step by step.
    upload_2017-1-16_14-5-49.png
     
  2. jcsd
  3. Jan 16, 2017 #2

    Math_QED

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    Homework Helper

    Your attempt is worth it! It shows us you made effort to solve the question.

    You have that ##y## must be equal to both ##\frac{1}{750} + \frac{8}{x}## and ##\frac{3}{2500} + \frac{12}{x}##

    Thus you need to solve for ##x##: ##\frac{1}{750} + \frac{8}{x} = \frac{3}{2500} + \frac{12}{x}## and then substitute your answer for ##x## to obtain the value for ##y##
     
  4. Jan 16, 2017 #3

    stevendaryl

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    Staff Emeritus
    Science Advisor

    The most straight-forward way to solve a system of equations (although not always the most efficient way) is:
    • Use the first equation to solve for one variable in terms of the rest
    • In the second equation, replace that variable by its value (found in step 1). This will give you an equation involving one fewer variable.
    • Now, solve for a second variable.
    • Continue for as many equations as you have (which should be the same as the number of variables)
    In your case, the first equation already gives you [itex]y[/itex] as a function of [itex]x[/itex]. So just use that value of [itex]y[/itex] in the second equation, and see what you get.
     
  5. Jan 16, 2017 #4
    Okay, so I did manage to solve it. I was stuck for some time on fractions. Thanks
     
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