Question

Algebraic expression of an arithmetic sequence is 6n+3. Find the sum of 1st 20 terms of the sequence, Find the algebraic expression of the sum​

Answer 1

Step-by-step explanation:

6n+3.

Find the sum of 1st 20 terms of the sequence

sum of an ap =N/2(first term+last term)

first term=9. {(6×1)+3}

last term =123. {(6×20)+3}

sum =20/2(123+9)

=10(131)

=1310

Find the algebraic expression of the sum

N/2\{9×(6n+3)}