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Find the nth term of an Arithmetic progression

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If the difference between successive pairs of terms is a constant then the series under examination is an arithmetic progression.

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Ths first term is \\(a\\) and the common difference is \\(d\\).

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The formula for the nth term of the series is given by:    \\(T_n=a+(n-1)d\\)

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In this example \\(a=\\var{a}\\),  \\(d = \\var{d}\\)  and  \\(n = \\var{n}\\)

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\\(T_\\var{n}=\\var{a}+\\simplify{{n}-1}*\\var{d}\\)

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\\(T_\\var{n}=\\var{a}+\\simplify{({n}-1)*{d}}\\)

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\\(T_\\var{n}=\\simplify{{a}+({n}-1)*{d}}\\)

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The first three terms of a series are given by:  

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\\(\\var{a} + \\simplify{{a}+{d}} + \\simplify{{a}+2*{d}}\\,+ \\, ...........\\)

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Calculate the $\\var{n}$ (st/th) term of the series.

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\\(u_\\var{n}=\\) [[0]]

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