Question

Find the rth term of an A.P sum of those forst n terms is 2n + 3n(sqaure)

Answer 1

Hi

Here is your answer,

Tn = Sn = Sn-₁

= (2n + 3n²) - [2(n - 1) + 3(n - 1)²]

= ( 2n + 3n²) - [ 2n - 2 + 3(n² + 1 - 2n)]

= 2n + 3n² - 2n + 2 - 3n² - 3 + 6n

= 6n - 1

∴ rth term (Tr) = 6r - 1



Hope it helps you !

Answer 2

hello...

Tn = Sn = Sn-1

(2n + 3n²) - [2(n - 1) + 3(n - 1)²]

( 2n + 3n²) - [ 2n - 2 + 3(n² + 1 - 2n)]

2n + 3n² - 2n + 2 - 3n² - 3 + 6n

6n - 1

rth term = 6r - 1