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Math Help - any general method

  1. #1
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    any general method

    In a coordinate system, if three points (5, 3), (x, 3) and (3, 2) lie on a same line, then find a value of x?
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  2. #2
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    Quote Originally Posted by bluffmaster.roy.007 View Post
    In a coordinate system, if three points (5, 3), (x, 3) and (3, 2) lie on a same line, then find a value of x?
    It's a straight line, therefore it has an equation of the form:

     y = mx+c

    Where m is the gradient and c is the y-intercept.

    To find m, use the following:

     m = \frac{y_2 - y_1}{x_2-x_1}

    Using the coordinates that have no unknowns.

    Then find the y intercept by plugging one of the coordinates into your new equation and solve for c.

    One you've done that, put the points (x,3) into the equation and solve for x.
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  3. #3
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    not able to solve can u show me how to since slope of

    the first two cordinates is zero so can the value of x be 5 ....what is the value of x
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  4. #4
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    Quote Originally Posted by bluffmaster.roy.007 View Post
    not able to solve can u show me how to since slope of

    the first two cordinates is zero so can the value of x be 5 ....what is the value of x
    The slope is not zero. You have two coordinates (5,3) and (3,2).

    Therefore, the gradient is calculated as follows:

     m = \frac{3-2}{5-3} = \frac{1}{2}

    So you know that the equation is:

     y = \frac{1}{2}x + C .

    Now you have to find C. Do this by taking one of the coordinates (either (5,3) or (3,2)) and plugging it into the equation, and solve for C.

     3 = \frac{1}{2} (5) + C

     \therefore C = 3 - \frac{5}{2}  = \frac{1}{2}

    So you're equation is  y = \frac{1}{2}x + \frac{1}{2}

    Now, plug in the coordinate (x,3) and solve for x.
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  5. #5
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    Quote Originally Posted by bluffmaster.roy.007 View Post
    In a coordinate system, if three points (5, 3), (x, 3) and (3, 2) lie on a same line, then find a value of x?
    If you plot (5, 3) and (3,2) and run a line through them it is clear that if (x, 3) lies on this line then x = 5.
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