SOLUTION: 9 divided by the difference of a number and 1 minus 8 divided by a number plus 1, equals 9 times the reciprocal of the difference of the number squared 1.

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Question 621492: 9 divided by the difference of a number and 1 minus 8 divided by a number plus 1, equals 9 times the reciprocal of the difference of the number squared 1.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Let n = "a number"
:
Assume the statement is:
"9 divided by the difference of a number and 1 minus 8 divided by a number plus 1, equals 9 times the reciprocal of the difference of the number squared and 1."
:
9%2F%28%28n-1%29%29 - 8%2F%28%28n%2B1%29%29 = 9(1%2F%28%28n%5E2-1%29%29)
we can factor the 3rd denominator, as the "difference of squares"
9%2F%28%28n-1%29%29 - 8%2F%28%28n%2B1%29%29 = 9(1%2F%28%28n-1%29%28n%2B1%29%29)
:
multiply by (x+1)(x-1), results gets rid of the denominators and we have
9(n+1) - 8(n-1) = 9
9n + 9 - 8n + 8 = 9
9n - 8n = 9 - 17
n = -8
:
:
Check this replace n with -8
9%2F%28%28-8-1%29%29 - 8%2F%28%28-8%2B1%29%29 = 9(1%2F%28%28-8%5E2-1%29%29)
9%2F%28-9%29 - 8%2F%28-7%29 = 9(1%2F%28%2864-1%29%29)
-1 + 8%2F7 = 9%2F63
-1 + 8%2F7 = 1%2F7