Question 1156431
Use logb(7)=1.946 and/or logb(4)=1.386 to find the logarithm of logb(1/7) 
<pre><b><u>Not needed:</b></u> {{{matrix(1,3, log (b, (4)), "=", 1.386)}}}
<b><u>Needed:</b></u>     {{{matrix(1,3, log (b, (7)), "=", 1.946)}}}
{{{highlight_green(matrix(1,7, log (b, (1/7)), "=", log (b, (1)) - log (b, (7)), "=", 0 - 1.946, "=", highlight(- 1.946)))}}}