Question

plzz explain it dear friends

Answer 1

Answer:

n = 3, r = 1/3

Step-by-step explanation:

equating the respective terms

n-1 /r = 6

n/r = 9

n-1 / r : n/ r

n-1 : n = 6 : 9

9 ( n-1) = 6 n

9n - 9 - 6n = 0

(÷3 )

3n -2n - 3 = 0

n -3 = 0

therefore , n = 3

substituting n in n / r

=> 3/r = 9

3 = 9 r

r = 3/9

r = 1/ 3

________(to determine r )

( or) n-1/r = 6

3-1 = 6 r

2 = 6 r

r = 2/6

r = 1/3

(or) n+1/r = 12

3+1 / r = 12

4 / r = 12

4 = 12 r

r = 4/12

r = 1/3