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    Two questions, that I can't seem to work out.
    1. Deduce the coefficient of x2 in the expansion of (3-x)(2+0.5x)8

    and

    2. Find the term independent of x in the expansion of (x- 2/x2)6

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    (Original post by Affection)
    Two questions, that I can't seem to work out.
    1. Deduce the coefficient of x2 in the expansion of (3-x)(2+0.5x)8

    and

    2. Find the term independent of x in the expansion of (x- 2/x2)6

    They both follow the same principle - if anything, the second one is easier than the first.

    For Q1 you want to work out how you are going to get a term involving x^2 in the final expansion. You have a 3 in the first bracket which mutlplies everything from the second bracket, so you will need the term in x^2 from that second bracket. Then you have a -x in the 1st bracket multiplying everything from the 2nd bracket, so you will need to use the term in x from that second bracket.

    Now just combine the 2 parts you have found.

    For Q2 use the binomial theorem to write down the general term from the expansion and work out a condition which produces the constant term i.e. power of x = 0.
 
 
 
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