Answer. 67
Explanation 100 - x2 + 15 X = 9
100 - (9) 2 + 15
100 - 18+15
100- 33
67
Answer:
1.66666666667
Step-by-step explanation:
Answer:
<u>The sequence is</u>
- 1, 1 + 2, 1 + 2 + 3, 1 + 2 + 3 + 4, ...
Each term is the sum of the consecutive numbers from 1 to that number.
<u>The nth term is the sum of the first n numbers:</u>
- aₙ = 1 + 2 + 3 + ... + n
- aₙ = 1/2n(1 + n) (formula for sum of the n terms of arithmetic progression with the first term of 1 and common difference of 1)
- aₙ = n(n + 1)/2
1) The number of circles in the nth pile is n(n + 1)/2
2) When n tends to infinity the number of circles tends to infinity
The answer is 3.6. Hope this helps!
