Question

Which of the following is the solution of log (x+3) 0.001 = -3 ?

x = 5
x = 7
x = 13
x = 15

Answer 1

x+3 is the base.

Answer 2

\[\log_{x+3} 0.001=-3\]
since 0.001=10^-3
so,\[\log_{x+3} 10^{-3} = -3\]
\[-3\log_{x+3} 10 = -3\]
\[\log_{x+3} 10=1\]
\[(\log10)/(log(x+3))=1\]
\[\log 10=\log(x+3)\]
hence, 10=x+3, x=7