Question 294351: Use the formula: s=n^2+n
all over 2
1. where S is the sum of the first n natural numbers. How
many consecutive natural numbers beginning with 1 will give a sum of 120 ?
2.where S is the sum of the first n natural numbers. How
many consecutive natural numbers beginning with 1 will give a sum of 253?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Use the formula: s=n^2+n
all over 2
1. where S is the sum of the first n natural numbers. How
many consecutive natural numbers beginning with 1 will give a sum of 120 ?
---
120 = (n^2+n)/2
n^2+n = 240
n^2+n-240 = 0
(n-15)(x+16) = 0
Positive solution:
n = 15 (# of natural numbers, 1,2,...n whose sum is 120
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2.where S is the sum of the first n natural numbers. How
many consecutive natural numbers beginning with 1 will give a sum of 253?
Use the same procedure as above.
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Cheers,
Stan H.
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