Difference between revisions of "2008 UNCO Math Contest II Problems/Problem 9"
(Created page with "== Problem == Let <math>C_n = 1+10 +10^2 + \cdots + 10^{n-1}.</math> (a) Prove that <math> 9C_n = 10^n -1.</math> (b) Prove that <math>(3C_3+ 2)^2 =112225.</math> (c) Prove t...") |
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== Solution == | == Solution == | ||
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== See Also == | == See Also == | ||
Revision as of 14:33, 26 November 2016
Problem
Let 
(a) Prove that 
(b) Prove that 
(c) Prove that each term in the following sequence is a perfect square:
![\[25, 1225, 112225, 11122225, 1111222225,\ldots\]](http://latex.artofproblemsolving.com/a/d/e/ade64d475ef0fa7c78ba6db494b757dcba52c0f0.png)
Solution
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See Also
| 2008 UNCO Math Contest II (Problems • Answer Key • Resources) | ||
| Preceded by Problem 8 |
Followed by Problem 10 | |
| 1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 | ||
| All UNCO Math Contest Problems and Solutions | ||
