Hmmm
\(\log_8{(x-1)}-\log_8{x}=1 \rightarrow\log_8{(\frac{x-1}{x})}=1\rightarrow\frac{x-1}{x}=8^1\rightarrow\frac{x-1}{x}=8\\\\ \rightarrow x-1=8x\rightarrow7x=-1\rightarrow x=-\frac{1}{7}\)
Slightly odd, as the original individual logarithms would only have complex values, though the combined log would be real (the imaginary parts cancel out).
Solve for x:
 (log(x-1))/(log(8))-(log(x))/(log(8)) = 1
 
 Rewrite the left hand side by combining fractions. (log(x-1))/(log(8))-(log(x))/(log(8))  =  (log(x-1)-log(x))/(log(8)):
 (log(x-1)-log(x))/(log(8)) = 1
 
 Multiply both sides by log(8):
 log(x-1)-log(x) = log(8)
 
 log(x-1)-log(x) = log(x-1)+log(1/x) = log((x-1)/x):
 log((x-1)/x) = log(8)
 
 Cancel logarithms by taking exp of both sides:
 (x-1)/x = 8
 
 Multiply both sides by x:
 x-1 = 8 x
 
 Subtract 8 x-1 from both sides:
 -7 x = 1
 
 Divide both sides by -7:
 Answer: | 
 | x = -1/7(assuming a complex-valued Logarithm)