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Determine the constant term in the expansion of (x+2)^9
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High School Teacher
The binomial expansion states `(a+b)^n=sum_(k=0)^n(nCk)a^(n-k)b^k`
In our case `(x+2)^9=sum_(k=0)^9(9Ck)x^(9-k)2^k`
The only term without x will be when k=9 => x^0=1. Hence that term will be equal to `9C9*1*2^9=1*1*512=512`
So the only constant is 512
Posted by rcmath on May 11, 2012 at 2:54 AM (Answer #1)
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