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Question
Find:
nth term of the A.P. 13, 8, 3, −2, ...
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Solution
13, 8, 3, −2...
We have:
\[a = 13\]
\[d = 8 - 13 = - 5\]
\[a_n = a + (n - 1)d\]
\[ = 13 + (n - 1)\left( - 5 \right)\]
\[ = 13 - 5n + 5\]
\[ = 18 - 5n\]
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