the 17th term of an ap is 5 more than twice its 8th term .if the 11th of an ap is 43, then find its nth term
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a₁₇ = 5 + 2a₈ and a₁₁ = 43
we know nth of an A.P. = a + (n-1) d where a = first term
d = common difference of A.P
therefore
a + (17 - 1) d = 5 + 2{ a + (8 - 1 ) d}
a + 16 d = 5 + 2a + 14d 2d - a = 5 .......(1)
also a + (11 - 1)d = 43 a + 10d = 43 .........(2)
solving 1 and 2 gives 12d = 48 d = 4
a = 3
hence nth tern would be = 3 + (n-1)4 ans
hope this helps
a₁₇ = 5 + 2a₈ and a₁₁ = 43
we know nth of an A.P. = a + (n-1) d where a = first term
d = common difference of A.P
therefore
a + (17 - 1) d = 5 + 2{ a + (8 - 1 ) d}
a + 16 d = 5 + 2a + 14d 2d - a = 5 .......(1)
also a + (11 - 1)d = 43 a + 10d = 43 .........(2)
solving 1 and 2 gives 12d = 48 d = 4
a = 3
hence nth tern would be = 3 + (n-1)4 ans
hope this helps
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