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Math Help - simultanious equation

  1. #1
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    simultanious equation

    hi,

    this is my question:
    Find the coordinates of the point where the line x-4y=3 intersects the line 3x+5x=26.

    i know i would do simultanious but would it be with these two:
    x-4y=3
    3x+5x=26

    rearange:

    -4y=-x+3
    8x=26?

    is this correct so far? if not where am i going wrong? also if this is correct, im not sure what to do next.

    thanks!
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  2. #2
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    e^(i*pi)'s Avatar
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    Re: simultanious equation

    Quote Originally Posted by andyboy179 View Post
    hi,

    this is my question:
    Find the coordinates of the point where the line x-4y=3 intersects the line 3x+5x=26.

    i know i would do simultanious but would it be with these two:
    x-4y=3
    3x+5x=26

    rearange:

    -4y=-x+3
    8x=26?

    is this correct so far? if not where am i going wrong? also if this is correct, im not sure what to do next.

    thanks!
    Is there a typo in the second equation?

    If there isn't then you can work out x just from the second equation and sub it's value into the first equation and find y

    So yes, you're right up to there. Now you need to find the value of x nd use it to find y
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  3. #3
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    Re: simultanious equation

    Quote Originally Posted by andyboy179 View Post
    hi,

    this is my question:
    Find the coordinates of the point where the line x-4y=3 intersects the line 3x+5x=26.

    i know i would do simultanious but would it be with these two:
    x-4y=3
    3x+5x=26

    rearange:

    -4y=-x+3
    8x=26?

    is this correct so far? if not where am i going wrong? also if this is correct, im not sure what to do next.

    thanks!
    Definitely correct so far. Like previously stated, just keep going with it. Divide 8 into 26 to have your x value, and then insert that number into your first equation and solve for y.
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  4. #4
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    Opalg's Avatar
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    Re: simultanious equation

    Quote Originally Posted by andyboy179 View Post
    hi,

    this is my question:
    Find the coordinates of the point where the line x-4y=3 intersects the line 3x+5x=26.
    You have almost certainly got the question wrong. The second equation should be 3x+5y=26. You can then solve the simultaneous equations in the usual way.
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  5. #5
    Junior Member BobBali's Avatar
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    Re: simultanious equation

    Make x the subject in the first equation> x= 4y+3 Now sub this into the second
    3(4y+3) +5y = 26
    12y+9 +5y = 26
    17y = 17
    y= 1 Sub this into > x = 4(1) +3 = 7 Hence, coordinates of intersection are (7,1)
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