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Math Help - simultaneous equation

  1. #1
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    simultaneous equation

    could anyone please show me a detailed method you could use for solving these simultaneous equations

    12x + 65y - 1 = 0 and

    60y = 150x + 511

    thanks for any help
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  2. #2
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    Quote Originally Posted by mark View Post
    could anyone please show me a detailed method you could use for solving these simultaneous equations

    12x + 65y - 1 = 0 and

    60y = 150x + 511

    thanks for any help

    Have you tried anything?

    Start by taking 1 equation and isolating a single variable, it doesn't matter which.
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  3. #3
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    i don't know what you mean by isolating a single variable. i've only started maths recently. i have tried things, like rearranging the top equation to match the bottom one in order. then make the x's or y's the same number and cancel them out. but i end up with 138 and 12/13 x = 511 and 12/13
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  4. #4
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    Quote Originally Posted by mark View Post
    i don't know what you mean by isolating a single variable. i've only started maths recently. i have tried things, like rearranging the top equation to match the bottom one in order. then make the x's or y's the same number and cancel them out. but i end up with 138 and 12/13 x = 511 and 12/13
    It means make it something like x = f(y) or y = f(x)

    For example: 12x +65y-1 = 0

    Add 1 to both sides and take 65y from both sides: 12x = 1 - 65y

    Divide by 12: x = \frac{1}{12}(1-65y)

    Now that x is expressed in terms of y you can put this into equation 2 wherever you see x
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  5. #5
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    thanks, the answer the book gave me was x = -3 and 1/6 and y= 3/5. could you show me how you would be able to express it that way please?
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  6. #6
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    Not sure what/why you're asking, Mark.

    From 12x + 65y - 1 = 0 we get x = (1 - 65y) / 12

    We substitute that in 60y = 150x + 511, to get:
    60y = 150(1 - 65y) / 12 + 511
    Solving gives y = 1047/1745 = 3/5

    Substituting y = 3/5 in 12x + 65y - 1 = 0 results in x = -19/6 or -3 1/6
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