Question 545889
{{{(a+b^-2)^-1}}}
get rid of the ^-1 with the reciprocal
{{{1/((a+b^-2))}}}
The reciprocal of b, then put it over a single denominator
{{{1/(a+(1/b^2))}}} = {{{1/((ab^2+1)/b^2)}}}
invert the dividing fraction and multiply
1 * {{{b^2/(ab^2+1)}}} or just {{{b^2/(ab^2+1)}}}