How does 32n-1 - 1 = (3n+1)(3n-1)
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It seems like the difference of 2 squares however I just can't work out how it factorises.
Find the relationship between x and y that does not involve logarithms:
log10(1+y) - log10(1-y) = x
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When I try to do this question i get `y = 10x - 10xy - 1 BUT the answer is y = (10x - 1) / (10x + 1)