Question

log 10 x - log 10 (x-4) =1 ?

Answer 1

\[\log_{10}x - \log_{10}x-4 =1\]
\[\log_{10}\frac{x}{x-4} = \log_{10}10\]
\[ \frac{x}{x-4} = 10\]
\[x =10x - 40\]
\[9x =40\]
\[x =\frac{40}{9}\]