\"\"

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The first term \"\", difference \"\" and n = 21.

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Find the nth term, so using the nth term formula: \"\".

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\"\"                   (Substitute \"\", and \"\")

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Distibute terms using distributive property: a(b – c)= ab – ac.

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\"\"

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\"\"                     (Product of two different signs is negative)

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\"\"                              (Product of two same signs is positive)\"\"

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Apply commutative property of addition: a + b = b + a.

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\"\"

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\"\"                                (Add: 5 + 10 = 15)

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Find the 21th term in the sequence.

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\"\"                          (Substitute n = 21)

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\"\"                                  (Multiply: \"\")

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\"\"                                             (Add: \"\") \"\"

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The 21th term of the arithmetic sequence \"\".