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put this solution on YOUR website!1/n+ 1/(n+1)= -1/n(n+1)
Add the 2 fractions on the left. To do that, get a common denominator
DEN = n(n+1), the same on the right side.
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(n+1)/DEN + n/DEN = -1/DEN
Multiply thru by DEN
(n+1) + n = -1
2n+1 = -1
2n = -2
n = -1
