Question

Need help fast!!!

Answer 1

@ganeshie8 @ParthKohli

Answer 2

@sleepyjess @imqwerty

Answer 3

@zepdrix

Answer 4

this is an arithmetic sequence whose common difference is 7.

Answer 5

the general formula for each term of an AP = a1 + (n-1)d

here d = 7 and a1 = 3 and n is the sequence number

Answer 6

so if we plug in values of 7 and 3 what do we get for the nth term ?

Answer 7

a1 = 3 , d = 7
so the nth term ( an ) = ?

Answer 8

sorry, i'm not sure

Answer 9

replace a1 by 3 and d by 7 :-

a1 + (n-1)d

= 3 + 7(n-1)

Answer 10

right!

Answer 11

ok, now what?

Answer 12

so in sigma notation the sum of 18 terms is