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Homework Help: Some Algebra questions.

  1. Aug 25, 2008 #1
    1. The problem statement, all variables and given/known data

    write an equation of the line:

    y intercept: negative 2
    x intercept: negative 1

    2. Relevant equations
    y


    3. The attempt at a solution

    i know its y equals mx plus b

    So b would equal negative two, but what about the y and the slope
     
  2. jcsd
  3. Aug 25, 2008 #2

    CompuChip

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    The x-intercept is the point where y = 0. In this case, that is at x = -1. If you plug that information into the general formula you will get an equation just for m.
     
  4. Aug 25, 2008 #3

    nicksauce

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    The slope, m, is the change in y divided by the change in x between two points (rise over run). You have two points, so you can find the slope.
     
  5. Aug 25, 2008 #4

    tiny-tim

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    Hi MoreZitiPlease! :smile:

    If you're not sure, write out the known coordinates:

    You know (0,-2) and (-1,0) are on the line.

    So -2 = m.0 + b

    0 = m.(-1) + b. :smile:
     
  6. Aug 25, 2008 #5

    symbolipoint

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    Standard Form equation for a line: Ax + By = C.

    You already have two points and they are the axes intercepts.
    A*0 + B*(-2) = C;
    A*(-1) + B*0 = C,
    But those might not help you since you get one equation with two unknowns.
    YOUR INERCEPTS are (0, -2) and (-1, 0), so just resort to y=mx+b general form and find the slope using the known points. Since you already have the y intercept, you can now plug all information into the general form.
     
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