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    Hey, so I've got a pretty basic problem off of one of my recent tests, but I'm really confused by the answer.

    Develop: (x – 3)^2

    I thought the answer would be x^2 - 9, but the answer is actually x^2 - 6x + 9.

    Can someone explain the steps, and what I did wrong?

    Thanks
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    (x - 3)^2 = (x - 3)(x - 3)

    Expand the right hand side, what do you get?

    And you know you must be wrong because clearly (10 - 9)^2 = (1)^2 = 1, where as you're claiming it should be 10^2 - 9^2 = 100 - 81 = 19. You can almost always check your answers to algebraic questions, so there's no excuse for getting them wrong.
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    (Original post by ec9999)
    Hey, so I've got a pretty basic problem off of one of my recent tests, but I'm really confused by the answer.

    Develop: (x – 3)^2

    I thought the answer would be x^2 - 9, but the answer is actually x^2 - 6x + 9.

    Can someone explain the steps, and what I did wrong?

    Thanks
    The expansion of the brackets can be done by using (a-b)^2=a^2-2ab+b^2 , however, in this case you have the strange word DEVELOP I have never seen this word in this context, so am puzzled.
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    ouch.
 
 
 

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