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Binomial Thoerem question (1 Viewer)

NizDiz

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Find the co-efficient of:

x in (1 + 2x + 3x^2) (1 - 2/x)^5
 

Drongoski

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When you multiply the first factor(a trinomial) with the binomial expansion, you can obtain terms in x only from the product of the 2nd term of the trinomial with the 1st (the constant term) of the expansion and the product of the 3rd term of the trinomial with the 2nd term of the expansion, which added together gives you (2-30)x


"how'd u do it so easily?": - if you have as many years of practice as I have, you'd be able to do it just as easily.
 
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braintic

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