Question

please answer for this question fastly. and for those correct answers I will mark you us a brainliest one. so please answer me fastly with correct answers plzzzzz please. ​

Answer 1

Answer:

1. Given,

a=5

d=9-5=4

We know,

an= l-(n-1)d

= 185 - (9-1)4

= 185 - 8×4

= 185 - 32

= 153

Therefore, 9th term is 153

2.So, the consecutive term of an ap

2k-1 - ( k+9 )=2k+7 -(2k -1)

2k-1 -k - 9 = 2k+7 -2k +1

k -10 = 8

k = 18

3. Given,

a=18

d=16 - 18= -2

We know,

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

= n/2 ( 2×18 + (n-1) -2 )=0

= n (36 -2n +2)=0

= n ( 38 -2n)

Either or

n=0 38 - 2n =0

= n= 19

Thus,the sum of 19 terms of the AP is 0