Question

solve this question ​

Answer 1

Answer:

Answer is 12

Step-by-step explanation:

Sum  = n/2 (2a + (n-1)d)

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

636 = n(9 + 4n- 4)

636 = 4n^2 + 5n

4n^2 + 5n - 636 = 0

x = 12 or - 13.25

Since the number of terms can't be negative

12 is the answer

Answer 2

Answer:

12

Step-by-step explanation:

.........666......