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Math Help - finind coeffitient

  1. #1
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    finind coeffitient

    i need to expand (x+5)^6
    iv got x^6+6(x)^5+15(x)^4+20(x)+15(x)+6(x)+5 Iv got that but i know iv missed out some powers as im not sure where there ment to go...Could someone help please?
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  2. #2
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    Code:
    1
    1 1
    1 2 1
    1 3 3 1
    1 4 6 4 1
    1 5 10 10 5 1
    That mean anything to you ?
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  3. #3
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    Hello, Chez_!

    You didn't include the second term . . .


    Expand: . (x+{\color{red}5})^6

    You should have: . x^6 + 6(x^5)({\color{red}5^1}) + 15(x^4)({\color{red}5^2}) + 20(x^3)({\color{red}5^3}) + 15(x^2)({\color{red}5^4}) + 6(x)({\color{red}5^5}) + {\color{red}5^6}

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  4. #4
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    not really lol
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  5. #5
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    do you know anything about the binomial expansion?
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  6. #6
    GAMMA Mathematics
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    Quote Originally Posted by bobak View Post
    do you know anything about the binomial expansion?
    Or Pascal's triangle (which is what bobak first showed you)?
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  7. #7
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    Quote Originally Posted by Chez_ View Post
    i need to expand (x+5)^6
    iv got x^6+6(x)^5+15(x)^4+20(x)+15(x)+6(x)+5 Iv got that but i know iv missed out some powers as im not sure where there ment to go...Could someone help please?
    It's long, but if you haven't been taught the fancier techniques there's nothing wrong with a little "elbow grease." Multiply it two terms at a time. Here's some markers for you so you can check your work:
    (x + 5)^6

    = (x + 5)(x + 5)(x + 5)(x + 5)(x + 5)(x + 5)

    = (x + 5)(x + 5)(x + 5)(x + 5)(x^2 + 10x + 5)

    = (x + 5)(x + 5)(x + 5)(x^3 + 15x^2 + 75x + 125)

    = (x + 5)(x + 5)(x^4 + 20x^3 + 150x^2 + 500x + 625)

    = (x + 5)(x^5 + 25x^4 + 250x^3 + 1250x^2 + 3125x + 3125

    and finally:
    = x^6 + 30x^5 + 375x^4 + 2500x^3 + 9375x^2 +18750x + 15625

    -Dan
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