SOLUTION: How would you solve this? I'm in ninth grade in Geometry 1 Honors: "Find the sum of the first 80 odd integers. Make your own term and value chart. Label the top row, 'number of odd

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Question 567156: How would you solve this? I'm in ninth grade in Geometry 1 Honors: "Find the sum of the first 80 odd integers. Make your own term and value chart. Label the top row, 'number of odd integers' and the bottom 'Sum'.
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
Let S_n be the sum of the first n odd (positive) integers (e.g. S_n = 1+3+...+(2n-1))

n---S_n
1 1
2 4
3 9
4 16
k k^2
80 80^2 = 6400

It can be proved using induction that the sum of the first k odd integers is k^2.