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*Showing that two lines are coincident - Help please.

  1. Sep 20, 2010 #1
    1. The problem statement, all variables and given/known data

    First off, this is a homework question, but an example so answer is given. need help understanding it.

    -Show that ht elines given by the equations below are coincident:
    L: 2x - y = 5
    M: -4x + 2y = -10

    Solution: Write each equation in slope-intercept form:

    L: 2x - y = 5
    -y = -2x + 5
    y = 2x - 5

    M: -4x + 2y = -10
    2y = 4x - 10
    y = 2x - 5

    Answer: The lines L and M have a slope of 2, and the same y intercept (0,5) so they are coincident.

    I dont understand how they got that answer of slope of 2 and y intercept of (0,5)


    2. Relevant equations

    3. The attempt at a solution

    Thanks everyone!
  2. jcsd
  3. Sep 21, 2010 #2


    Staff: Mentor

    The y-intercept for these lines is NOT at (0, 5). Check your book again to see what it says.
    There are several forms of the equation of a line.
    What is the slope-intercept form?
    What information does the slope-intercept form of the equation of a line contain?
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