Math, asked by chandni52, 1 year ago

find the sum of 51terms of an AP whose second and third terms are 14 and 18res​

Answers

Answered by shemeemaariz
0

Answer:

if 2nd term is 14

and 3 term is 18

The common difference is 3rd term minus 2nd term (the two are concecutive)

ie common difference is 4

if common difference is 4

then second term can be written as

a+d ie a+4=14

the a is 10

the sum of number is

51/2(2•10+(50-1) 4)

=706

Answered by abinabhiraj
5

Answer:5610

Step-by-step explanation:

Since the 2nd term of AP is 14

a+(n-1)d=14

Where

a+(2-1)d=14

a+d=14----(1)

And the 3rd term of the AP is 18

a+(n-1)d=18

a+(3-1)d=18

a+2d=18----(2)

By subtracting (1) from (2)

We get

d=4, a=10

Formula for finding the sum of a specific nth term is

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

In this case

S51=(51/2)(20+(50*4))

=(51/2)(20+200)

=(51/2)(220)

=5610

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