Question 19401
{{{b = (b-a)/(a)}}}
{{{ab = b-a}}}
{{{ab - b = -a}}}
{{{b(a - 1) = -a}}}
{{{b = -a/(a-1)}}}


or, tidying up the negative sign, we can do the following:


{{{b = -a/((-1)(-a+1))}}}
{{{b = -a/((-1)(1-a))}}}
{{{b = a/(1-a)}}}


jon.