Find the 12th term from the end of the AP – 2, - 4, - 6, …, - 100.

1.	Find the 12th term from the end of the AP – 2, - 4, - 6, …, - 100.
Answer» Given AP, – 2, - 4, - 6, …, - 100. Here, first term, a = - 2 common difference, d = - 4 – (2) = - 2 last term, l = - 100. We know that, the nth term 'a_n' of an AP from the end is a_n = l - (n - 1)d where l is the last term and d is the common difference. 12th term from the end, a₁₂ = - 100 - (12 - 1) - 2 = - 100 + 22 = - 78 Hence, the 12th term from the end is - 78

Answer»

Given AP, – 2, - 4, - 6, …, - 100.

Here,

first term, a = - 2

common difference, d = - 4 – (2) = - 2

last term, l = - 100.

We know that, the nth term 'a_n' of an AP from the end is

a_n = l - (n - 1)d

where l is the last term and d is the common difference.

12th term from the end,

a₁₂ = - 100 - (12 - 1) - 2

= - 100 + 22

= - 78

Hence, the 12th term from the end is - 78

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