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Homework Help: Expanding and simplifying brackets

  1. Feb 16, 2010 #1
    Could someone please expain where I went wrong with this?

    expand and simplify the following:
    1/8(6x - 12y) + 1/2(3x + 2y)

    I expanded the brackets like this:
    0.75x - 1.5y + 1.5x + y

    and simplified like this:
    2.25x - 0.5y

    But the right answer is: 2.25x - 2.5y
  2. jcsd
  3. Feb 16, 2010 #2


    Staff: Mentor

    Your answer is correct for the problem you showed. Are you sure you copied the problem correctly? If so, the "right" answer is wrong.
  4. Feb 16, 2010 #3
    Thanks Mark.
    There must have been a misprint on the answer page of my book.
    I have the same problem with this one.

    1/5(15x + 10y) + 3/10(5x - 5y)

    My answer is: 4.5x + 0.5y

    The book says it should be: 4.5x -0.5y

    Have I made a mistake or is the book wrong again?
    Thanks once again for your help.
  5. Feb 16, 2010 #4


    Staff: Mentor

    Assuming you have written the problem as it appears in the book, your answer is correct.
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