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Homework Help: *Quick Linear equation - Equation of a line - Thanks

  1. Sep 26, 2010 #1
    1. The problem statement, all variables and given/known data

    Determine an equation of a line through -3,5 and 1, -3

    so...... What i got is

    y - 5 = -2(x-(-3) )

    So that turns into

    y - 5 = -2x + 3 correct?

    now i am suppose to simplify, and the answer is

    y = -2x -1

    how did they get y = -2x -1 from y - 5 =-2x + 3

    ?? Can anyone please explain the steps they did to get that final answer?


    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Sep 26, 2010 #2
    y - 5 = -2(x-(-3) ) Does NOT turn into y - 5 = -2x + 3?

    Deal with the double negative first, then distribute the -2 to ALL terms it’s multiplied by, so:

    y - 5 = -2(x-(-3) ) -> y - 5 = -2(x+3) -> y - 5 = -2x-6 -> y= -2x-1
     
  4. Sep 26, 2010 #3
    wow, thanks. That makes much more sense!

    ok so y - 5 = -2x-6

    now you to get rid of the y - 5, you ad 5 to both sides correct?


    y= -2x-1


     
  5. Sep 26, 2010 #4

    Mark44

    Staff: Mentor

    You're not getting rid of y - 5 - you're just isolating y to get it all by itself. Yes, you add 5 to both sides.
     
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