SOLUTION: Hello, I need help with the following problem: For what integer {{{ n }}} is {{{ (10^n-1)(10^n+1) }}} = 999,999,999,999?

Algebra ->  Square-cubic-other-roots -> SOLUTION: Hello, I need help with the following problem: For what integer {{{ n }}} is {{{ (10^n-1)(10^n+1) }}} = 999,999,999,999?       Log On


   

Question 1047624: Hello,
I need help with the following problem:
For what integer +n+ is +%2810%5En-1%29%2810%5En%2B1%29+ = 999,999,999,999?
Found 2 solutions by stanbon, Alan3354:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
(10^n-1)(10^n+1) = 999,999,999,999
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10^(2n)-1 = 1,000,000,000,000-1
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10^(2n) = 10^12
2n = 12
n = 6
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Cheers,
Stan H.
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Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
For what integer n is %2810%5En-1%29%2A%2810%5En%2B1%29+=+999999999999?
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%2810%5En-1%29%2A%2810%5En%2B1%29+=+10%5E12+-+1+
10%5E%282n%29+-+1+=+10%5E12+-+1+
2n = 12
n = 6