Question 1065508
Numerator: {{{16b^2-1=(4b-1)(4b+1)}}}
Denominator cannot be factored to integers. 
To determine the domain, find when the denominator is equal to zero and exclude these values from the domain,
{{{b^2+11b-6=0}}}
{{{b^2+11b+(11/2)^2=6+(11/2)^2}}}
{{{(b+11/2)^2=24/4+121/4}}}
{{{(b+11/2)^2=145/4}}}
{{{b+11/2=0 +- sqrt(145)/2}}}
{{{b=-11/2+- sqrt(145)/2}}}
So the domain is all reals except these two b values,
{{{b=-11/2+sqrt(145)/2}}}
and
{{{b=-11/2-sqrt(145)/2}}}