Question 35387
{{{((a+b)/b )does not equal a}}}

for e.g {{{(3+2)/3 = 5/3}}} 
NOT {{{2/3}}}

{{{(x^(-1)+y^(-1))/((x^-1)y))}}} I am guessing you mean this and not {{{X^(-1y)}}}

={{{ ((1/x)+(1/y))/(Y/X)}}}

= {{{((y+x)/xy)*(X/Y)}}}

Now you can cancel the common X to give you
{{{((y+x)/y^2)}}}
which is your final answer.