Question

find the sum of AP 34,32,...,10​

Answer 1

Answer:

Sn = n / 2 [ 70 + 2n ] is the required answer

Step-by-step explanation:

The given AP is = 34 , 32 , ....... , 10

therefore we have ,

first term = a = 34

common difference = d = 32 - 34 = - 2

so the Sn = n/2 [ 2a + (n-1) d ]

⇒ Sn = n / 2 [ 2( 34 ) + (n-1) -2 ]

⇒ Sn = n / 2 [ 68 - 2n + 2 ]

⇒ Sn = n / 2 [ 70 + 2n ]