Question

if the 19th term of an ap is 47 then find the sum of its first 37 terms.
PLEASE GIVE THE ANSWER STEP BY STEP.
AND PLEASE DON'T POST THE SILLY ANSWER.

Answer 1

Hii There!!!


Let 'a' be the first term and 'd' be the common difference of the given A.P

★According to the question.

=)a₁₉ = 47

⇒ a + 18d = 47 ----1)

Since, Sum of the first n terms of an AP is given by :-

Sn = n/2 {2a + (n - 1)d}

=) 37/2 {2a + (37 - 1)d}

=) 37/2 {2a + 36d}

=) 37 {2a + 18d}

Substituting the value of a + 18d = 47 in the above, we get ;

=) 37 × 47
=) 1739

So, the sum of the first 37 terms is 1739

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Hope it helps