Results 1 to 3 of 3

Math Help - Plz Help

  1. #1
    Junior Member
    Joined
    Jun 2005
    Posts
    58

    Plz Help

    Write an equation in slope-intercept form of the line passing through each pair of points: (6, -2) and (3, -4)

    -4 - (-2)
    --------- = -2/3
    3 - 6


    next

    y - (-2) = -2/3(x - 6)
    y - (-2) -2/3x -9
    y - (-2) + (-2) = -2/3x -9 + (-2)

    y= -2/3x + 7 <-- my answer.

    Let me now if I'm correct or wrong?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Apr 2005
    Posts
    1,631
    Your idea is correct.
    You tried to find the slope of the line.
    Then you used that slope in the point-slope form of the equation of the line.

    But your solution/answer is wrong.
    Mistakes in the Algebra. I'd say, mistakes due to skipping steps.

    -4 - (-2)
    --------- = -2/3
    3 - 6

    Maybe if you did not skip one step you could have got the correct slope.
    Like this:
    -4 - (-2)
    --------- = -2/(-3) = 2/3 <---the correct slope is positive.
    3 - 6


    next

    y - (-2) = (2/3)(x - 6)
    y - (-2) = (2/3)x -(2/3)6
    y - (-2) = (2/3)x -4
    y -(-2) +(-2) = (2/3)x -4 +(-2)

    y = (2/3)x -6 <----answer.

    ---------
    Of course it is okay to skip steps. But if you are not that good yet, maybe it's good for you to do it step by step.

    ----------
    Also, to check if your answer is correct, you test your answer with the given data.

    So your answer is
    y = -(2/3)x +7

    See if that is correct by plugging, say, (6,-2) into your answer.
    Like so,
    -2 = -(2/3)6 +7
    -2 = -4 +7
    -2 = 3
    No, they are not equal, so your answer is not correct.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Jun 2005
    Posts
    58
    Thanks for the help.
    Follow Math Help Forum on Facebook and Google+

Search Tags


/mathhelpforum @mathhelpforum