Question

How mang terms of the Ap
18, 16, 14 .... to be taken sam
is zero​

Answer 1

Answer:

19

Step-by-step explanation:

a=18

d=-2

sn=0

Answer 2

Answer:

Step-by-step explanation:

Here,

let a=18, d=16-18= -2, no. of terms be 'n'

So, Sn= n/2[2a+(n-1)d]=0 ( because we want sum as zero)

=>0= n/2[ 2x18 +(-2)(n-1)]

=>0= n/2[36-2n+2]

=>0= 36n-2n^2+2n

=>0 = 2n^2-2n-36

if u solve this by Shreedharacharya formula or quadratic formula,

n= 37/2 = 18.5 and n= -35/2( rejected because no. of terms can't be -ve)

so approx. 19 terms should be taken to make the sum 0