On 06/06/2015 19:07, tim..... wrote:
"Farmer Giles" wrote in message
...
On 06/06/2015 11:15, tim..... wrote:
"Tim Streater" wrote in message
.. .
In article , Tim Watts
wrote:
Prove that: n^2-n-90=0
For n = -9 or n = 10, easy enough to do in one's head.
That's a solution
not a proof
tim
Correct, it is not a proof - neither was my answer earlier.
This is, though: 6/n x 5/n-1 = 1/3
-- 30/n^2-n = 1/3
-- 90 = n^2-n -- 0 = n^2-n-90
but it's still not a proof in the context of a maths question, which is
prove that n = 10 (from the information in the question, not from the
equation)
There is no requirement to "prove" n=10 (and finding that n=10 would be
finding a solution, not providing a proof)
--
Cheers,
John.
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