List the first 10 terms of these sequences:1) The sequence obtained by starting with 10 and obtaining each term by subtracting 3 from the previous term2) The sequence whose n-th term is the sum of the first n positive integers

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Bornejecbo · Accepted Answer

I made only the first one.1) As we know that       a    1    =  10      a    2    =  10  −  3  =  7      a    3    =  7  −  3  =  4      a    4    =  4  −  3  =  1      a    5    =  1  −  3  =  −  2      a    6    =  −  2  −  3  =  −  5      a    7    =  −  5  −  3  =  −  8      a    8    =  −  8  −  3  =  −  11      a    9    =  −  11  −  3  =  −  14      a          10        =  −  14  −  3  =  −  17      a          n      +      1        =      a    n    −  3 as       a    1    =  10  ,  n  ≥  1

Brenden Tran · Accepted Answer

(2) As       a    n    =  1  +  2  +  3  +  …  +  n      a    1    =  1      a    2    =  1  +  2  =  3      a    3    =  1  +  2  +  3  =  6      a    4    =  1  +  2  +  3  +  4  =  10      a    5    =  1  +  2  +  3  +  4  +  5  =  15      a    6    =  1  +  2  +  3  +  4  +  5  +  6  =  21      a    7    =  1  +  2  +  3  +  4  +  5  +  6  +  7  =  28      a    8    =  1  +  2  +  3  +  4  +  5  +  6  +  7  +  8  =  36      a    9    =  1  +  2  +  3  +  4  +  5  +  6  +  7  +  8  +  9  =  45      a          10        =  1  +  2  +  3  +  4  +  5  +  6  +  7  +  8  +  9  +  10  =  55

List the first 10 terms of these sequences: 1) The sequence

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