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Math Help - System of equations- please help!

  1. #1
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    System of equations- please help!

    Here's a system of equations I'm really stuck on:

    x=4/3y
    4/3x=7+y

    Solve for y
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  2. #2
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    Re: System of equations- please help!

    Does "4/3y" mean (4/3)y? Assuming that and "4/3x" means (4/3)x, just replace the x in the second equation by (4/3)y:
    (4/3)x= (4/3)(4/3)y= (16/9)y= 7+ y. Now subtract y from both sides.

    (If "4/3y" means 4/(3y) and "4/3x" means 4/(3x), much the same: 4/(3(4/3y))= (4/3)(3y/4)= y= 7+ y which is impossible.)
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  3. #3
    MHF Contributor MarkFL's Avatar
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    Re: System of equations- please help!

    Use the first equation to substitute for x in the second, and this will give you an equation in y alone, that you can then solve. What do you find?
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