Question 20718
Did you know that log{{{n}}}m - log {{{n}}}b can be re-written as 
log{{{n}}}{{{m/b}}}

So you now get log{{{2}}}{{{(2x+8)/(2x^2+21x+61)}}} = -3

-3 can be re-written as -3 x 1
and 1 can re-written as log{{{2}}}2
which means you now get log{{{2}}}{{{2^(-3)}}}


As it is log{{{2}}} on both sides now, you can take away the log.

So you get {{{(2x+8)/(2x^2+21x+61)}}} = {{{2^(-3)}}}

Can you solve it from here?