Question

plz solve ques 36.....​

Answer 1

Answer:

there are 12 terms

Step-by-step explanation:

given

Sn=636

a(first term)=9

d(common difference)=8

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

636=n/2[18+(n-1)8]

1272=18n+8n^2-8n

1272=8n^2+10n

8n^2+10n-1272=0

4n^2+5n-636=0

4n^2+(53-48)n-636=0

4n^2+53n-48n-636=0

n(4n+53)-12(4n+53)=0

(4n+53) (n-12)

if 4n+53=0

n=-53/4

if n-12=0

n=12

n is never equal to 53 by 4 so n is 12

Answer 2

There are 12 term

given

Sn=636

a(first term) =9

d(common difference ) =8

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

636=n/2[18+(n-1)8]

1272=18n+8n^2-8n

1272=8n^2+10n

8n^2+10n-1272=0

4n^2+5n-636=0

4n^2+(53-48)n-636=0

4n^2+53n-48n-63=0

n(4n+53)-12(4n+53)=0

(4n+53)(n-12)

if 4n+53=0

n=53/4

if n-12=0

n=12

n is never equal to 53 by 4 so n is 12 .

Hope it helps you......