Question

the sum of n terms of an ap is 5n2-3n.find ap and its 10th term
pls help me to answer this question
get 50 points by answering correct question

Answer 1

Ahoy! Refer to the attachment

In the question it's given:- 5n^2 - 3n

Then we got the values of a1 , a2 , a3

Common difference :- a2 - a1

:- 22 - 12 = 10

Finally a10 = a + (n - 1)d

:- 2+ (9)(10)

:- 2 + 90

:- 92

_______________________________

Answer 2

Answer:

If $5n^{2}-3n$ is the sum of n terms of an AP, then its 10 the term is 92

Step-by-step explanation:

Given
Sum of n terms of the AP is $5n^{2}-3n$

So sum of 10 terms of the AP :

S 10 = $5*10^{2}-(3*10)$

= (5*100)-(30)

= 500-30

=470

Also sum of 9 terms of the AP:

S 9= $5*9^{2}-(3*9)$

=(5*81)-(27)

=405-27

=378

So, 10 the term = sum of 10 terms - sum of 9 terms

= 470-378

=92

So, the 10 the term is 92