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anonymous

  • one year ago

Find a if the coefficient of x^7 in the expansion of (3x + a) ^12 is -228096

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  1. triciaal
    • one year ago
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    Paschal's Triangle Binomial Theorem

  2. triciaal
    • one year ago
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    |dw:1441167013634:dw|

  3. triciaal
    • one year ago
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    |dw:1441167247659:dw|

  4. triciaal
    • one year ago
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    |dw:1441167559412:dw|

  5. triciaal
    • one year ago
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    @jim_thompson5910 this looks messy but do you agree?

  6. triciaal
    • one year ago
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    @Zale101 is there a better way to do this?

  7. jim_thompson5910
    • one year ago
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    @triciaal you forgot about raising 3 to the 7th power

  8. triciaal
    • one year ago
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    @jim_thompson5910 in the substitution yes thanks

  9. triciaal
    • one year ago
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    |dw:1441206453306:dw|

  10. triciaal
    • one year ago
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    |dw:1441206724641:dw|

  11. jmark
    • one year ago
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    x^7 will be the 6th term. Hence, using binomial expansion 12C5*3^5*a^5*x^7 = 228096. Solving a^5 = 1.1852. Benefits of Literacy http://blog.tutorvista.com/2015/09/benefit-of-literacy/

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